function popUp(URL) {
         day = new Date();
         id = day.getTime();
         eval("page" + id + " = window.open(URL, '" + id + "', 'toolbar=0,scrollbars=0,location=0,statusbar=0,menubar=0,resizable=1,width=900,height=400,left=400,top=100');");
     }

function findAddress() {
         popUp('/GetAddress.aspx?postcode=' + document.form1.tbPostCode.value);
     }