Using 2 functions at the same time to validate form

Question

im trying to put to javascript functions that will validate a form, but cant make it work. This is what i have :

<script type="text/javascript" language="JavaScript">
    function checkForm(f)
    {
        if (f.elements['val1'].value == "")
        {
            alert("Por favor insere o valor correcto do subsidio");
            return false;
        }
        else
        {
            f.submit();
            return false;
        }
    }

    function IsNumeric(sText)
    {
       var ValidChars = "0123456789.";
       var IsNumber=true;
       var Char;

       for (i = 0; i < sText.length && IsNumber == true; i++) 
       { 
           Char = sText.charAt(i); 
           if (ValidChars.indexOf(Char) == -1) 
           {
               alert("O valor que introduziu não é válido");
               IsNumber = false;
           }
       }
       return IsNumber;
    }
</script>

    <form method="post" onSubmit="return checkForm(this); return IsNumeric(this); return false;" action="<?php echo $_SERVER['PHP_SELF']; ?>">

The first function works, but the second one that will only allow numbers and decimal points dont work. (Not sure if the second function is right)

Can someone hel me out?

Sincerely

Answer 1

Try returning this instead:

<form onSubmit="return checkForm(this) && IsNumeric(this.elements['val1'].value)">

The return statement stops executing the proceeding code, and the IsNumber function is never called.

By the way: You can validate a number like this:

function IsNumeric(txt){ return parseFloat(txt) == txt; }

Answer 2

You're returning the value of the first function and are therefore stopping the is number function from running.

You need to call is number in your checkForm function.

<script type="text/javascript" language="JavaScript">
function checkForm(f)
{
    if (f.elements['val1'].value == "")
    {
        alert("Por favor insere o valor correcto do subsidio");
        return false;
    }
    else
    {
        return IsNumeric(f.elements['val1'].value);
    }
}

    function IsNumeric(sText)

    {
       var ValidChars = "0123456789.";
       var IsNumber=true;
       var Char;


       for (i = 0; i < sText.length && IsNumber == true; i++) 
          { 
          Char = sText.charAt(i); 
          if (ValidChars.indexOf(Char) == -1) 
             {
            alert("O valor que introduziu não é válido");
             IsNumber = false;
             }
          }
       return IsNumber;

       }
    </script>

    <form method="post" onSubmit="return checkForm(this);" action="<?php echo $_SERVER['PHP_SELF']; ?>">

Answer 3

Simpler version

<script type="text/javascript" language="JavaScript">
function checkForm(f) {
  var val = f.elements['val1'].value; 
  if (val.length==0) { // blank
    alert("Por favor insere o valor");
    return false;
  }
  if (isNaN(val)) { // not numeric
    alert("Por favor insere o valor correcto do subsidio");
    return false;
  }
  // here the value is a number and filled in
  return true; // no need for else after a return
}
</script>

<form method="post" onSubmit="return checkForm(this);" action="<?php echo $_SERVER['PHP_SELF']; ?>">