/**
       * Validates if the character pressed is digit 
       * @param evt
       * @return
       */     
      function isDigitsOnly(evt)
      {
         var charCode = (evt.which) ? evt.which : evt.keyCode
         if (charCode > 31 && (charCode < 48 || charCode > 57))
            return false;

         return true;
      }
     
      /**
       * Validates if the character pressed is Arabic character 
       * @param evt
       * @return
       */
      function isArabicLetterOnly(evt)
      {
         var charCode = (evt.which) ? evt.which : evt.keyCode
         if (charCode > 31 && (charCode < 1569 || charCode > 1618))
            return false;

         return true;
      }
      
      
      /**
       * Validates if the character pressed is English character 
       * @param evt
       * @return
       */
      function isEnglishLetterOnly(evt)
      {
         var charCode = (evt.which) ? evt.which : evt.keyCode
         if (charCode > 31 && (charCode < 65 || charCode > 90) && (charCode < 97 || charCode > 122)) 
            return false;

         return true;
      }