Remove URL Field in Comments

Now a days lot of spamming is going in the internet activity , in order to reduce spam people use captcha's even after using captcha code, spammers are spamming blogs and websites. Then i found a  way to remove url field in WordPress comments. In order to remove URL field in comments., add the following snippet in your functions.php file.

add_filter('comment_form_default_fields', 'unset_url_field');
function unset_url_field($fields){
    if(isset($fields['url']))
       unset($fields['url']);
       return $fields;
}

Now URl field is not displayed in the comments section.