$(document).ready(function(){

	var height =$(window).height()-$("#ftr").outerHeight();
	var presentHeight= $("#wrap").height();

	if(height-presentHeight>0){
		$("#wrap").height(height);
		var element = document.getElementById("p_top");
		if(element!=null){
			element.style.position = 'absolute';
			element.style.bottom = '0';
		}
	}
});