Create URL Slug from text string [PHP]

<?php

/*
Name : PHP function to Create URL Slug from a text string

It is great tool for generating SEO URLs.
*/

function createUrlSlugFromString($string){
	
	// Remove spaces from front and end of the string
	$string = strtolower(trim($string));
	
	// Change all non-alphanumeric character sequences to -
	$string = preg_replace('/[^a-z0-9-]/', '-', $string);
	
	// Change multiple hyphens to single hyphens
	$urlSlug = preg_replace('/-+/', "-", $string);
	
	// Remove trailing - from the slug
	$urlSlug=trim($urlSlug,"-");
	
	// We are done! Now return the sluf back.
	return $urlSlug;
	
} // End of Create URL Slug from a text string function


// Calling the URL Slug creation function
echo createUrlSlugFromString ( " This is some text with     multiple spaces and punctionations (,.?)");

?>