$(document).ready(function(){
var stylepath = $('#stylepath').val();
var snum = $('#head_bg').data('id');
function GetRandomNum(Min, Max) {
    var Range = Max - Min, Rand = Math.random();
    return Min + Math.round(Rand * Range);
}
var pic = piclist;
	for(var i=0;i<pic.length;i++){
	pic[i] = stylepath+pic[i]['picurl'];
}
var x = GetRandomNum(0, snum-1);
window.onload = function() {
    document.getElementById("head_bg").style.backgroundImage ="url("+pic[x]+")";
}});