pls help me with "IsNaN function"

• • Reply

  19 years ago

  by persisprue

  persisprue

  , United States

  Joined 19 years ago

  hie! i'm having some trouble using the IsNaN function...i hope to validate the age to determine whether it is numeric or not before submitting the form.....
  i want the function to return false when it is not a number ...but function isNaN returns true when it is not a number.....
  any other function i can use???
  

  
  pls help...below is my codes..it is not working....
  

  
  thanks in advance
  

  
  

  
  <SCRIPT>  
  function Validator(theForm)
  if (IsNaN(frmCusInfo.txtAge.value))
    {  
     alert("Please enter a numeric number for the \"Age\" field.");
     frmCusInfo.txtAge.focus();
  //  return (false);    i want this function to return false
  }    
  </SCRIPT>
  

  
  <FORM name=frmCusInfo  onsubmit="return Validator(this)" method=post>
  

  
  ...
  

  
  <INPUT name=txtAge type=text style="HEIGHT: 22px; WIDTH: 26px">
  

  
  

  
  ....
  

  
  </FORM>
  

  
  

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• • Reply

  19 years ago

  by tlkelley

  Super Tal

  Montgomery, United States

  Joined 19 years ago

  First thing, whenever you pull a field value in JavaScript it always returns a string.
  This, frmCusInfo.txtAge.value, will always return a string.
  

  
  Try using Regular Expressions or look below at my example.
  

  
  Let's look at my example below where I only allow dollar amounts and formatting.  You can modify to fit your needs.
  

  
  <!-- Function Description:  Validates Non Currencys fields. -->
  

  
  function validateDollar( fld )
  {
     var temp_value = fld.value;
  

  
     if (tempvalue == "")
     {
       fld.value = "$0.00";
       return;
     }
     var Chars = "0123456789.,$";
     for (var i = 0; i < tempvalue.length; i++)
     {
         if (Chars.indexOf(temp_value.charAt(i)) == -1)
         {
             alert("Invalid Character(s)\n\nOnly numbers (0-9), a dollar sign, a comma, and a period are allowed in this field.");
             fld.focus();
             fld.select();
             return;
         }
     }
  }
  

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  18 years ago

  by paulfp

  Paul Freeman-Powell

  Liverpool, United Kingdom

  Joined 19 years ago

  string = document.form.text.value;
  number = parseInt(string);
  document.write(number);
  

  
  that sorta think should help ya

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