isajax flag

isajax flag

I'm adding is a flag to indicate that a post was sent via ajax. Is there a better way to do this so that I don't have to add the flag  every time an ajax form is posted?

var param = $("#"+frmId).serializeArray();
 param.push({"name":"isajax","value":1});
  $("#shoppingcart").load("/catalog/shoppingcart.php", param);