// Launch Presentations
function LaunchPres(x){
    var winl = (screen.width-990)/2; 
    var wint = (screen.height-630)/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=990,height=630 top='+wint+',left='+winl+'')
}