Validate file extension and let an empty field be OK

Hi,
i use the following to validate wether the file for upload is in a valid format. I would like the script to allow an empty field also.
--------------------
function ValFileField(entered, alertbox) {
   with (entered){
      ext=value.substr(value.lastIndexOf(".")).toLowerCase();

      if (ext!=".jpg"&&ext!=".gif"&&ext!=".bmp"&&ext!=".png"){
         if (alertbox!="") {
           alert(alertbox);
        }
        return false;
    }
    else {
      return true;
    }
  }
}
------------------------------
jenmatAsked:
Who is Participating?
 
ZvonkoConnect With a Mentor Systems architectCommented:
Or like this:

function ValFileField(entered, alertbox) {
  with (entered){
     ext=value.substr(value.lastIndexOf(".")).toLowerCase();

     if (ext!=""&&ext!=".jpg"&&ext!=".gif"&&ext!=".bmp"&&ext!=".png"){
        if (alertbox!="") {
          alert(alertbox);
       }
       return false;
   }
   else {
     return true;
   }
 }
}

0
 
venkateshwarrCommented:

function ValFileField(entered, alertbox)
{
  if (entered.value=="") return true;

  with (entered){
      ext=value.substr(value.lastIndexOf(".")).toLowerCase();

      if (ext!=".jpg"&&ext!=".gif"&&ext!=".bmp"&&ext!=".png"){
         if (alertbox!="") {
           alert(alertbox);
        }
        return false;
    }
    else {
      return true;
    }
  }
}
0
 
ZvonkoSystems architectCommented:
Thanks for points.

But next time please consider to split the points to all experts who helped you.

See you,
Zvonko
0
 
jenmatAuthor Commented:
Will do, just thought your solution were better because it had less code.

venkateshwarr, i apologies / Jens
0
 
venkateshwarrCommented:

Thats ok..
0
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