Javascript and PHP - Variable Passing

[space1]

I am trying to use a variable (calculated in Javascript) and then use it in a SQl query that I'll run in PHP.
My problem is that I can't figure out the syntax to use...I want to pass a Javascript variable into my SQL script
that I'll then run in PHP. And if this is not possible, what is another alternative?

This is the Javascript:
<form name="formName"><input type="text" name="textName"></form>
<script language="JavaScript"><!--
document.formName.textName.value = location.search.substring(1);
var sEventTitle = location.search.substring(1);
alert (sEventTitle);
//--></script>

This is the PHP/SQL: [This is the part that is not working]
<?php
$sql = "SELECT FROM tEvents WHERE Title = <script language='JavaScript'>sEventTitle</script>";
echo "sql = " . $sql;
$vQueryResult_1 = mysql_query($sql) or die($Err_msg_1 . "&nbsp;&nbsp;&nbsp;Error Msg = " . mysql_error() . $Err_msg_2 );
// ********************* END of Error Msg **********************
$login_check = mysql_num_rows($vQueryResult_1);
Etc....

[dalecosp]

You can't run a server-side Javascript in this manner, I don't think. Calculate the variable in Javascript on the client side, and either submit it in the form's URL (GET method) or write it to a cookie on the client machine and have PHP read it via $_COOKIE['varname'] ...

HTH,

[cgraz]

just to expand on dalecosp's post, javascript is client-side (executed on the local computer), whereas php is server-side(executed on the server). PHP gets executed on the server and parsed to display in the users browser. So php would be executed before javascript. This means that you can't take a javascript variable (which is processed after the php) and pass it over to mysql using php (because php is processed before the javascript). I hope this made sense.

Cgraz

[pyro]

Also, another method of passing a value from javascript to PHP is simply via the query string. You could pass the value of your javascript variable sEventTitle to the PHP page like this:

<script type="text/javascript">
top.location.href = "yourpage.php?value="+sEventTitle;
</script>

Then, on your PHP page, you can get it using $SERVER["QUERY_STRING"] or $GET["value"]