Whats wrong with this?

//Function to jump to another forum
function ForumJump(URL) {
 
 if (URL.options[URL.selectedIndex].value != "") self.location.href = URL.options[URL.selectedIndex].value; 
 return true;
}

//Function to open pop up window
function openWin(theURL,winName,features) {
   window.open(theURL,winName,features);
}

//Function to open preview post window
function OpenPreviewWindow(targetPage, formName){
 
 now = new Date 
 
 //Open the window first  
    openWin('','preview','toolbar=0,location=0,status=0,me nubar=0,scrollbars=1,resizable=1,width=680,height=400')
     
    //Now submit form to the new window
    formName.action = targetPage + "?ID=" + now.getTime(); 
 formName.target = "preview";
 formName.submit();
}