Scenario:

I have two objects viz:'Application' and 'Application Efforts'.'Application' is parent and 'Application Efforts' is child.Both have the lookup relationship.I want  to show 'Application Efforts' records in a table on the basis of 'Application' selected in picklist.

I am using the following code and its not working.

VF Page:

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<apex:page standardController="Quote__c" extensions="mycheck">
    <apex:form >
        <apex:pageBlock >
            <apex:pageBlockSection title="Application Efforts:">
                <apex:selectList value="{!selectedApplication3}" label="Select Application:" size="1" onchange="chngtxt()">
                    <apex:selectOptions value="{!ApplicationOptions2}">   
                    </apex:selectOptions>
                </apex:selectList>  
                <apex:actionFunction  name="chngtxt" action="{!change6}" reRender="intxt5" id="chngtxt"/>
                <apex:repeat value="{!lstAppEffort}" var="al" id="intxt5">
                {!al.Application_ID__r.Name__c}
                
                </apex:repeat>
            </apex:pageBlockSection>
        </apex:pageBlock>
    </apex:form>
</apex:page>

Controller:

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public with sharing class mycheck {

    public string selectedApplication3 {get;set;}
    public List<SelectOption> ApplicationOptions2 { get;set;}
    public List<Application__c> LstApplication{get;set;}
    public List<Application_Efforts__c> lstAppEffort{get;set;}
    public mycheck(ApexPages.StandardController controller) {
        ApplicationOptions2 = new List<SelectOption>();
        LstApplication=[select Name__c from Application__c];
        ApplicationOptions2.add(new SelectOption('Please Select','Please Select'));
        for(Application__c appobj:LstApplication){
            ApplicationOptions2.add(new SelectOption(appobj.Name__c,appobj.Name__c));
        }
    }
    public void change6(){  
        lstAppEffort = [select id,Application_ID__r.Name__c,Effort_Level_ID__c,Effort_Duration_ID__c,Effort_Hours__c from Application_Efforts__c where
                            Application_ID__r.id = :selectedApplication3];
    }

}

A quick help in this regard is highly appretiated.