var aPlaceHolders = new Array();

//on page load call PH_init
$(document).ready(PH_init);
//add text to var elements that have a class of .PH_*
function PH_init(){
    for (var phItem in aPlaceHolders) {
        $("var.PH_"+phItem).append(aPlaceHolders[phItem]);
    }
}