// Launch Presentations
function LaunchPres(x){
    var winl = (screen.width-925)/2; 
    var wint = (screen.height-1000)/2; 
    window.open('presentations/pres.php?pres=' + x,'Slideshow_Window','toolbar=no,location=no,directories=no,status=no,menubar=no,scrollbars=no,resizable=no,copyhistory=no,width=925,height=627 top='+wint+',left='+winl+'')
}