create client side javascript alert in php

[greedyisg00d]

I have 2 date fields namely date_from and date_to. A javascript alert pops out when date_from is ahead of date_to for example

date_from: 2009-04-25
date_to: 2009-04-11

I manage to validate this correctly but after deploying my site the validation is done on the server side maybe because I hard coded the javascript function inside php.

Any idea on how can I fix this? Thanks in advance!

[Krik]

First javascript can not run on the server side, it can only run in the users browser.

Second showing us your code is the fastest way to get help. We really don't like typing out a bunch of code especially when it may not work with what you already are working with. It just needs to be the absolutely most relevant parts

[greedyisg00d]

Seems your right and I need to recode my page again. Now what I want is to create a validation using javascript alert whenever the user clicks on the submit button. Here is my code from before using php

if(isset($_POST['btnAdd'])){
if(  ($date_from > $date_to) )
					echo "<script type='text/javascript'> window.alert('Date_From must not be greater than Date_To');  </script>";
}			

Sample codes is much appreciated. Thanks

[Krik]

If you want an alert it may be better to validate in javascript.

In your <form> tag you can use the "onsubmit" event to call a function. You then can have the function check fields. And if they are not valid generate an alert and "return false" to stop the form submission.

<script>
function check_form() {
    if (!check_field(document.getElementById('name'))) return false;
}

function check_field(field) {
   if (field.value.length < 8) {
       alert('Please fill in all required fields');
       field.focus;
       return false;
   }
   else {
       return true;
   }
}
</script>

Obviously you can create much more complex validation code but it gives you the general idea.