using javascript in an IF statement

[ukscotth]

Hi,

 

I'm trying to work out how I can trigger a javascript popup type box in an if statement, to trigger it normally from a button it would be :

 

<input type="button" value="Display" onclick="javascript: formFunction();" class="submit" />

 

But I want to use it when people submit a form without filling in some of the fields so something like this :

 

if  (($_POST['first_name'] == '')) { run javascript popup }

 

Any ideas ?

 

Many thanks in advance.

 

Scott

[Buddski]

It aint pretty but it does what you want.

if  (($_POST['first_name'] == '')) { echo '<script type="text/javascript"> alert(\'this is an alert box\');</script>'; }

 

Wouldnt it be better to verify the data using javascript before it gets posted to the server and then floods the user with incomplete field popups? Just a thought.

[ukscotth]

Thanks,

 

Unfortunatly the person im doing the site for wants a facebook style popup for some strange reason

[Buddski]

You can replace the alert box that I wrote with any other javascript function.

Facebook style popups will require HTML etc inside them so it should be left till the end of script execution..

AKA.. store all the errors (if any) when the page is loaded make your pretty little popup..

 

From a user stand point, its less intrusive.

 

Example:

if (isset($_POST['submitted'])) {
$errors = array();
// do all your error checking
}

 

Bottom of the page:

<?php if (isset($errors) && !empty($errors))  { ?>
<script type="text/javscript">
    javascriptErrorHandler('<?php echo join(',',$errors); ?>');
</script>
<?php } ?>
</body>
</html>

[ukscotth]

Thanks il give it a try. Sorry for being a newbie but what would I put in the :

 

// do all your error checking

 

All it needs to check is 2 fields

 

Thanks again.

[Buddski]

Check that the field is set, that it isnt empty and any other error checking that the field may require.

(ie, has to be a number, can only be alpha, is an email etc etc)

Where is the data going once it has been submitted?

[ukscotth]

Ok so i put something like this ?

 

if (isset($_POST['submitted'])) {
$errors = array();

if (($_POST['from'] == "") || ($_POST['to'] == "")){
}

 

The data will be sent to another page as example.php?from=example&to=example

[ukscotth]

ok hes just told me that a normal alert box is fine but when i do this it messes up the styling on the page

 

if(isset($_POST['submit'])){


if (($_POST['from'] == "") || ($_POST['to'] == "")){



}else{

header( 'Location:quote_part1.php?from='.$_POST['from'].'&to='.$_POST['to'] ) ;

}

}

any ideas why ?

thanks.

[ukscotth]

sorry i meant to put

 

if(isset($_POST['submit'])){


if (($_POST['from'] == "") || ($_POST['to'] == "")){
?>
 <script type="text/javascript">
window.alert("You message goes here!")
</script>
<?php


}else{

header( 'Location:quote_part1.php?from='.$_POST['from'].'&to='.$_POST['to'] ) ;

}

}

[Buddski]

Where are you putting this header call? After there has been code output to the browser?

[ukscotth]

nope at the very top

[Buddski]

If the style has broken (in my experience), it usually means text/an error has been displayed at the top of the page.

Can you show me the code from line 1 until the end of this bit of script.

[ukscotth]

Problem solved.

 

I used this code to check the fields before they were submitted

 

<script language="javascript" type="text/javascript">
function checker()
{
var myForm = this.document.myForm;
	if(myForm.from.value == '')	
	    {
		     alert("Please Select the pick up area");
			 myForm.from.focus();
			 return false;
	    }


	if(myForm.to.value == '')
		{
			alert("Please Select the droping area");
			myForm.to.focus();
			return false;
		}

	if(myForm.from.value == myForm.to.value)
		{
			alert("Pick up area and droping area should not be same");
			myForm.to.focus();
			return false;
		}


}
</script>

 

Thanks alot for your help, its most appreciated