function populate_customer_details(){
    $.ajax({
        type : 'POST',
        url : 'populate_customer_details.php',
        data: {
            email : $('#txt_email_id').val()
        },
        success : function(data){
            if(data=="NOROWSFOUND"){
                alert("Sorry, Email ID not exist in our database"); 
                document.getElementById("txt_email_id").focus();    
            }else{
                var val = explode_all_into_arr(data,"|=|");
                document.getElementById("FirstName").value = val[0];
                document.getElementById("LastName").value = val[1];
                document.getElementById("mobilecountrycode").value = parseInt(val[2]);
                document.getElementById("MobileNo").value = val[3];
                document.getElementById("homecountrycode").value = parseInt(val[4]);
                document.getElementById("HomeNo").value = val[5];
                document.getElementById("PaxEmail").value = val[6];
                document.getElementById("PaxEmailConf").value = val[6];
            }
        },
    });
}
This is my snippet purpose is getting the customer details and populate into textfield and combo box ,
That is 
Firstname will append into Firstname text field ,
Secondname will append into Secondname text field ,
Same like mobilecountrycode (but this is dropdown combo), 
Some time combo selectedindex work fine, but some time not selecting the value ,
I am not sure what s problem in that...
Nothing works in IE ,
Also showing object expected error in IE ,
i have ajax_common.js : in this i added above script ,
in the page top first i included the jquery.js ,
Then i include ajax_common.js file,
But no idea why this problem.
Regards
(NOTE i included the jquery.js )
,