We build a vf page for an custom object called competitor.  The vf page consists of java script for executing pop up box according to our senario.
The java part of the code is as below: function chngPrimComp(cmp,val){       
        var c;
        var flag=0;
        if(cmp.checked==false && flag!=0){           
            alert('{!$Label.msgCantUnchk}');
            cmp.checked=true;
            flag++;
        }
        if(cmp.checked==true && flag==0){             
            ctrlCompetitor.checkFirstPrimaryComp('{!$CurrentPage.parameters.retURL}',function(result, event){
                if(event.status){           
                    if(result=='false'){                   
                    c=confirm('{!$Label.msgPrmryCompCnfrm}');
                        if(c==true){
                        flag++;                              
                            ctrlCompetitor.checkPrimaryComp('{!$CurrentPage.parameters.retURL}',function(result, event){
                                if(event.status){}
                                if(event.exception){}
                            });
                        }
                        else if(c==false){
                        cmp.checked=false;
                        }
                    }
                }  
            });
Senario: Opportunity had competitor has a related list. ---> This competitor had few records. if we edit the record from opportunity page,the logic work fine and it displays popup.
In this case the logic captures the opportunity id {!$CurrentPage.parameters.retURL}' =>
ctrlCompetitor.checkFirstPrimaryComp('/006c0000009gG4Q',function(result, event){

Problem:if i edit the competitor records from competitor page then the code didn't fire pop up.

In this case the logic captures opprotunity id along with addtional info .something like this heckFirstPrimaryComp('/a0G?rlid=00ND0000005Df4w&id=006c0000009gG4Q',function(result, event){

 Bug:In the above case how to truncate the additional values and how to display popup on the competitor if user edits from competitor page.