php file
<?php
function myfunc()
{
//code here
}
?>
<script>
var ur="ajaxc-alling-file.php";
</script>
<script src="custom.js"></script>
js file
jQuery(document).ready(function(){
var geturl=ur;
alert(geturl);
});
Result will be display in alert box "ajaxc-alling-file.php"