$("input:visible:enabled:first").focus();

//Integer Input validation function 
function ValInt(Field) {
 var value = Field.value;
 for(var i = 0; i < value.length; i++) {
  var ch = value.charAt(i);
  if(ch < '0' || ch > '9') {
   alert ('Invalid number');
   Field.focus();
   Field.select();
   return false;
  }
 }
 return true;
}

//Checks for right number of characters
function ValLength(Field,Length) {
 var value = Field.value;
 if((value.length!=Length) && (value.length>0)) {
      alert ('Invalid Field Length');
   Field.focus();
   Field.select();
   return false;
  }
 return true;
}


//  Email Input validation function :
function ValidEmail(Field)
{
 var s = Field.value;
 
 if(isEmail(s) == false)
 {
    alert ('Invalid email format');
    Field.focus();
    Field.select();
    return false;
 }
  return true;
}
 
function isEmail (s)
{   
    // there must be >= 1 character before @, so we
    // start looking at character position 1
    // (i.e. second character)
    var i = 1;
    var sLength = s.length;
     if (sLength==0)
         return true;
 
    // look for @
    while ((i < sLength) && (s.charAt(i) != "@"))
    { i++
    }
 
    if ((i >= sLength) || (s.charAt(i) != "@")) return false;
    else i += 2;
 
    // look for .
    while ((i < sLength) && (s.charAt(i) != "."))
    { i++
    }
 
    // there must be at least one character after the .
    if ((i >= sLength - 1) || (s.charAt(i) != ".")) return false;
    else return true;
}