function getbrowserwidth()


                           {
                               if (navigator.userAgent.indexOf("MSIE") > 0)


                                       {
                                               return(document.body.clientWidth);
                                       }
                               else


                                   {
                                               return window.outerWidth;
                                       }
                               }
                               function getbrowserheight()


                                   {
                                       if (navigator.userAgent.indexOf("MSIE") > 0)


                                               {
                                                       return(document.body.clientHeight);
                                               } 
                                       else


                                           {
                                                       return(window.outerHeight);
                                               }
                                       }
                                       var popup = new Object()
                                       function CenterPopup(URL, width, height)


                                           {
                                               // get center of browser window
                                               var X = getbrowserwidth() / 2
                                               var Y = getbrowserheight() / 2
                                               
                                               popup = window.open(URL, 'PopUp', 
                                                       'scrollbars=yes ' +
                                                       'width=' + width + ' ' +
                                                       'height=' + height + ' ' +
                                                       'top=' + (window.screenTop + (Y - (height/2))) + ' ' +
                                                       'left=' + (window.screenLeft + (X - (width/2))) 
                                                       )
                                               
                                               popup.focus()
                                       }