Wrote this function to check email addresses already in a database, so I dont have to change pages, and check with javascript. Problem: it exposes your whole email list to the public in the source code, and the source code can become a monster length. So it isnt practical, but it works. (I'm not using it to check emails)

The script proves useful to do other things with javascript and spawn arrays to manipulate data... etc.

function jarray(){

$sql = "SELECT * FROM table_name LIMIT 0, 100000000";
$jarray = "var your_array = new Array();\n\t\t";
$i = 0;
$q = mysql_query($sql);
while($object = mysql_fetch_object($q)){
$jarray = $jarray."your_array[{$i}] = \"{$object->field_name}\";\n\t\t";
$i++;
}

print $jarray."\n";
}

Put your own info where the Text is bold