function keyfilter(e, ctype)
        {
        var keynum;
        var keychar;
        var keycheck;

        if (ctype == 0){ keycheck = /[0-9]/; }
        if (ctype == 1){ keycheck = /[0-9\.\,]/; }
        if (ctype == 2){ keycheck = /[a-zA-Z0-9]/; }
        
        if(window.event) // IE
          {
          keynum = e.keyCode;
          }
        else if(e.which) // Netscape/Firefox/Opera
          {
          keynum = e.which;
          }
        else
          {
          return true;
          }
          
        keychar = String.fromCharCode(keynum);
        
        //Edit chars: tab, del, enter, backspace, left, right
        if (keynum == 9 || keynum == 46 || keynum == 13 || keynum == 8 || keynum == 37 || keynum == 39)
          {
          return true;
          }

        if (keycheck.test(keychar))
          {
          return true;
          }
        return false;
        }