That is a javascript function from Cute Editor
In CuteSoft_Client\CuteEditor\Scripts\IE_Implementation\CuteEditorImplementation.js
function ShowDialog(handler,url,args,feature)
{
var win=_dialogWindow||window;
_dialogWindow=null;
return Window_ShowDialog(win,handler,url,args,feature);
}
function Window_ShowDialog(win,handler,url,args,feature)
{
var res=win.showModalDialog(url,args,feature);
if(handler)
{
win.setTimeout(function CallHandler(){
//alert(handler);
handler(res);
},1);
}
return;
}