var regFormWinName = "RegForm";

// 
function launchRegForm() {

    // open a completely empty window as fast as possible
    // then target that window with the form post
    var winRef = window.open("about:blank", regFormWinName, "toolbar=0,location=0,directories=0,status=1,menubar=0,resizable=1,width=600,height=600");
    winRef.focus(); 
}