Form Validation

Check String Length

function stringlength(inputtxt, minlength, maxlength) { 
var field = inputtxt.value; 
var mnlen = minlength;
var mxlen = maxlength;

if(field.length<mnlen || field.length> mxlen) { 
    alert("Please input the userid between " +mnlen+ " and " +mxlen+ " characters");
    return false;
}else{ 
    alert('Your userid have accepted.');
    return true;
}}

Checking for all numbers

function allnumericplusminus(inputtxt)
   {
      var numbers = /^[-+]?[0-9]+$/;
      if(inputtxt.value.match(numbers))
      {
      alert('Correct...Try another');
      document.form1.text1.focus();
      return true;
      }
      else
      {
      alert('Please input correct format');
      document.form1.text1.focus();
      return false;
      }
   }

Checking for all letters

function allLetter(inputtxt)
  {
   var letters = /^[A-Za-z]+$/;
   if(inputtxt.value.match(letters))
     {
      return true;
     }
   else
     {
     alert("message");
     return false;
     }
  }