php variable passed to mysql query

Not sure what I am doing wrong? Never ran into this issue before? But this is also the first function I have written.

<?php
function category($string){
if(preg_match("/(Slimming|Laser|Spa|Massage|Manicure|Pedicure)/i", $string)){  
echo 'Spa';
}
}  // This is function.php

$title = 'Spa';

include 'function.php';
$category = category($title);
$category = mysql_real_escape_string($category);
echo 开发者_StackOverflow社区"$category<br>"; // I get Spa
var_dump("$category"); //added for testing, I get string(0) ""

$category is then sent to a mysql insert, the value is blank in the database...

Thanks for the help.

echo 'Spa';

Should be:

return 'Spa';

and

var_dump("$category");

Should be:

var_dump($category);

Functions should always return a value if you're defining a variable otherwise you're doing nothing.

You get the ouput "Spa" when you call category($title), because in the function is echo instead of return.