compare js var to php var

hello,

I loaded data from DB and print it in form:

query = mysql_query("SELECT cont FROM `some_table` WHERE id = $id ");
$index = mysql_fetch_array($query);
$cont  = $index['cont'];

echo "<form method='post' action='index.php'>
<textarea name='description' value='$cont'>$cont</textarea>
</form>";

PHP:

I want the script to compare the content of value $cont with the new text that I'll write in the TEXTAREA
I need it to be on the client side, means - when I click SUBMIT, the script will be run and will giving me massage if the text in the TEXTAREA was change (not equal to value $cont).

Thank you all in advanced,
Roi.

 

echo "<script type='text/javascript'>";
echo "function chkSubmit() {";
echo "    var cont = '$cont'";
echo "    if (document.getElementById( 'description' ).value == cont) {";
echo "          alert('Value matches');";
echo "        //document.getElementById( 'formname' ).submit();";
echo "    } else {";
echo "          alert('Value does not match');";
echo "        //document.getElementById( 'formid' ).submit();";
echo "    }";
echo "}";
echo "</script>";
echo "<form method='post' name='formname' id='formid' action='index.php'><textarea name='description' id='description'>$cont</textarea>";
echo "<input type='button' name='process' value='Submit' onclick='javascript:chkSubmit();'/>";
echo "</form>";

Code (markup):

Submit of the form is disabled, so if you want to submit the form in the case of match or a missmatch then just uncomment the submit line in javascript //document.getElementById( 'formid' ).submit(); by removing //

 

Thank you!

 

echo "        //document.getElementById( 'formname' ).submit();";

Code (markup):

should be

echo "        //document.getElementById( 'formid' ).submit();";

Code (markup):

in line 6. Oops