function popupWindow(mypage, myname, w, h, scroll, isResizable) {
        var winl = (screen.width - w) / 2;
        var wint = (screen.height - h) / 2;
        var winprops = 'height='+h+',width='+w+',top='+wint+',left='+winl+',scrollbars='+scroll+',resizable='+isResizable;
        var win = window.open(mypage, myname, winprops);
        if (parseInt(navigator.appVersion) >= 4) {
            win.window.focus();
        }
}
// ==================================================== //

function emailCheck(str) {
         var at="@"
         var dot="."
         var lat=str.indexOf(at)
         var lstr=str.length
         var ldot=str.indexOf(dot)
         if (str.indexOf(at)==-1){
          alert("Invalid E-mail ID")
          return false
         }
         if (str.indexOf(at)==-1 || str.indexOf(at)==0 || str.indexOf(at)==lstr){
          alert("Invalid E-mail ID")
          return false
         }
         if (str.indexOf(dot)==-1 || str.indexOf(dot)==0 || str.indexOf(dot)==lstr){
           alert("Invalid E-mail ID")
           return false
         }
         if (str.indexOf(at,(lat+1))!=-1){
           alert("Invalid E-mail ID")
           return false
         }
         if (str.substring(lat-1,lat)==dot || str.substring(lat+1,lat+2)==dot){
           alert("Invalid E-mail ID")
           return false
         }
         if (str.indexOf(dot,(lat+2))==-1){
           alert("Invalid E-mail ID")
           return false
         }
         if (str.indexOf(" ")!=-1){
           alert("Invalid E-mail ID")
           return false
         }
         return true
}