[jquery] Populate dropdown select with array using jQuery

function validateForm(){
    var success = true;
    resetErrorMessages();
    var myArray = [];
    $(".linkedServiceDonationPurpose").each(function(){
        myArray.push($(this).val())
    });

    $(".linkedServiceDonationPurpose").each(function(){
    for ( var i = 0; i < myArray.length; i = i + 1 ) {
        for ( var j = i+1; j < myArray.length; j = j + 1 )
            if(myArray[i] == myArray[j] &&  $(this).val() == myArray[j]){
                $(this).next( "div" ).html('Duplicate item selected');
                success=false;
           }
        } 
    });
    if (success) {
        return true;
    } else {
        return false;
    }
    function resetErrorMessages() {
        $(".error").each(function(){
            $(this).html('');
        });``
    }
}