I have been playing around with a VF page and I can't figure out why i am getting this error the code saves fine. I did not write the code I am just trying to edit it. 

Here is the VF code  I underlined and bolded the code I added 


I have been playing around with a VF page and I can't figure out why i am getting this error the code saves fine. I did not write the code I am just trying to edit it.
 
 
<apex:page standardController="Opportunity" extensions="opportunityProductEntryExtension" action="{!priceBookCheck}" >
 
    <apex:sectionHeader Title="Manage {!$ObjectType.Product2.LabelPlural}" subtitle="{!opportunity.Name}"/>
    <apex:messages style="color:red"/>
 
    <style>
        .search{
            font-size:14pt;
            margin-right: 20px;   
        }
        .fyi{
            color:red;
            font-style:italic;
        }
        .label{
            margin-right:10px;
            font-weight:bold;
        }
    </style>
   
    <script type='text/javascript'>
   
        // This script assists the search bar functionality
        // It will execute a search only after the user has stopped typing for more than 1 second
        // To raise the time between when the user stops typing and the search, edit the following variable:
       
        var waitTime = 1;
       
   
        var countDown = waitTime+1;
        var started = false;
       
        function resetTimer(){
       
            countDown=waitTime+1;
           
            if(started==false){
                started=true;
                runCountDown();
            }
        }
       
        function runCountDown(){
       
            countDown--;
           
            if(countDown<=0){
                fetchResults();
                started=false;
            }
            else{
                window.setTimeout(runCountDown,1000);
            }
        }
   
    </script>
  
 
    <apex:form >
   
        <apex:outputPanel id="mainBody">
       
            <apex:outputLabel styleClass="label">PriceBook: </apex:outputLabel>
            <apex:outputText value="{!theBook.Name}"/>&nbsp;
            <apex:commandLink action="{!changePricebook}" value="change" immediate="true"/>
            <br/>
            <!-- not everyone is using multi-currency, so this section may or may not show -->
            <apex:outputPanel rendered="{!multipleCurrencies}">
                <apex:outputLabel styleClass="label">Currency: </apex:outputLabel>
                <apex:outputText value="{!chosenCurrency}"/>
                <br/>
            </apex:outputPanel>
            <br/>
           
<!-- this is the upper table... a.k.a. the "Shopping Cart"-->
 
            <!-- notice we use a lot of $ObjectType merge fields... I did that because if you have changed the labels of fields or objects it will reflect your own lingo -->
            <apex:pageBlock title="Selected {!$ObjectType.Product2.LabelPlural}" id="selected">
                      
                <apex:pageblockTable value="{!shoppingCart}" var="s">
                <apex:column >
                        <apex:commandLink value="Remove" action="{!removeFromShoppingCart}" reRender="selected,searchResults" immediate="true">
                            <!-- this param is how we send an argument to the controller, so it knows which row we clicked 'remove' on -->
                            <apex:param value="{!s.PriceBookEntryId}" assignTo="{!toUnselect}" name="toUnselect"/>
                        </apex:commandLink>
                    </apex:column>
                   
                    <apex:column headerValue="{!$ObjectType.Product2.LabelPlural}" value="{!s.PriceBookEntry.Product2.Name}"/>
                   
                    <apex:column headerValue="{!$ObjectType.OpportunityLineItem.Fields.Quantity.Label}">
                        <apex:inputField value="{!s.Quantity}" style="width:70px" required="true" onkeyup="refreshTotals();"/>
                    </apex:column>
                   
                      <apex:column headerValue="{!$ObjectType.OpportunityLineItem.Fields.Product_Type__c.label}">
                        <apex:inputField value="{!s.Product_Type__c}" style="width:70px" required="true" onkeyup="refreshTotals();"/>
                    </apex:column>
                   
                    <apex:column headerValue="{!$ObjectType.OpportunityLineItem.Fields.Terms__c.label}">
                        <apex:inputField value="{!s.Terms__c}" style="width:70px" required="true" onkeyup="refreshTotals();"/>
                    </apex:column>
                   
                    <apex:column headerValue="{!$ObjectType.OpportunityLineItem.Fields.Tearms_Legth__c.label}">
                        <apex:inputField value="{!s.Tearms_Legth__c}" style="width:70px" required="true" onkeyup="refreshTotals();"/>
                    </apex:column>
                  
                    <apex:column headerValue="{!$ObjectType.OpportunityLineItem.Fields.UnitPrice.Label}">
                        <apex:inputField value="{!s.UnitPrice}" style="width:70px" required="true" onkeyup="refreshTotals();"/>
                    </apex:column>
                   
                    <apex:column headerValue="{!$ObjectType.OpportunityLineItem.Fields.Description.Label}">
                        <apex:inputField value="{!s.Description}" required="false"/>
                    </apex:column>
                   
                </apex:pageblockTable>
           
           
                <apex:pageBlockButtons >
                    <apex:commandButton action="{!onSave}" value="Save"/>
                    <apex:commandButton action="{!onCancel}" value="Cancel" immediate="true"/>
                </apex:pageBlockButtons>
           
            </apex:pageBlock>
   
<!-- this is the lower table: search bar and search results -->
   
            <apex:pageBlock >
           
                <apex:outputPanel styleClass="search">
                    Search for {!$ObjectType.Product2.LabelPlural}:
                </apex:outputPanel>
 
                <apex:actionRegion renderRegionOnly="false" immediate="true">
               
                    <apex:actionFunction name="fetchResults" action="{!updateAvailableList}" reRender="searchResults" status="searchStatus"/>
                    
                    <!-- here we invoke the scripting to get out fancy 'no button' search bar to work -->
                    <apex:inputText value="{!searchString}" onkeydown="if(event.keyCode==13){this.blur();}else{resetTimer();}" style="width:300px"/>
                    &nbsp;&nbsp;
                    <i>
                        <!-- actionStatus component makes it easy to let the user know when a search is underway -->
                        <apex:actionStatus id="searchStatus" startText="searching..." stopText=" "/>
                    </i>
                   
                </apex:actionRegion>
           
                <br/>
                <br/>
           
                <apex:outputPanel id="searchResults">
               
                    <apex:pageBlockTable value="{!AvailableProducts}" var="a">
                   
                        <apex:column headerValue="{!$ObjectType.Product2.Fields.Name.Label}" value="{!a.Product2.Name}" />
                       
                        <apex:column headerValue="{!$ObjectType.Product2.Fields.Family.Label}" value="{!a.Product2.Family}"/>
                       
                        <apex:column headerValue="{!$ObjectType.Product2.Fields.Description.Label}" value="{!a.Product2.Description}"/>
                       
                         <apex:column headerValue="{!$ObjectType.Product2.Fields.Product_Type__c.Label}" value="{!a.Product2.Product_Type__c}"/>
                       
                        <apex:column headerValue="{!$ObjectType.Product2.Fields.Terms__c.Label}" value="{!a.Product2.Terms__c}"/>
                       
                        <apex:column >
                            <!-- command button in a column... neato -->
                            <apex:commandButton value="Select" action="{!addToShoppingCart}" reRender="selected,searchResults" immediate="true">
                                <!-- again we use apex:param to be able to tell the controller which row we are working with -->
                                <apex:param value="{!a.Id}" assignTo="{!toSelect}" name="toSelect"/>
                            </apex:commandButton>
                        </apex:column>
                       
                    </apex:pageBlockTable>
                   
                    <!-- We put up a warning if results exceed 100 rows -->
                    <apex:outputPanel styleClass="fyi" rendered="{!overLimit}">
                        <br/>
                        Your search returned over 100 results, use a more specific search string if you do not see the desired {!$ObjectType.Product2.Label}.
                        <br/>
                    </apex:outputPanel>
                    
                </apex:outputPanel>
           
            </apex:pageBlock>
           
        </apex:outputPanel>
 
    </apex:form>
 
</apex:page>