PHP Post data to url with curl

I know you will need sometimes to use a php code to send data (text) to an url using POST method, just like it was sent by a form.
So all you have to do now, is to copy this function and use it, you have to specify the url and the data to post and it goes !

<?php
function post_content($url,$nfields,$fields_string)  
{
    $ch = curl_init();  
    curl_setopt($ch, CURLOPT_URL, $url);  
    curl_setopt($ch,CURLOPT_POST,$nfields);
    curl_setopt($ch,CURLOPT_POSTFIELDS,$fields_string);
    curl_setopt($ch, CURLOPT_HEADER, 1);
    curl_setopt($ch, CURLOPT_USERAGENT, 'Mozilla/5.0 (Windows; U; MSIE 7.0; Windows NT 6.0; en-US)');  
    ob_start();  
    curl_exec ($ch);  
    curl_close ($ch);  
    $string = ob_get_contents();  
    ob_end_clean();  
    return $string;      
}
?>

How this will work ? It's very easy:
1- First you need to know what url you want to post to using curl
2- You need to know what are the names of variables to post (textarea, checkbox..)
3- Their number
4-And their values

This is a quite easy exemple:
if the original form has these fields: textarea1, textarea2, and sends to "www.site.com/page.php", like this example:

<form name="form1" method="post" action="www.site.com/page.php">
  <textarea name="textarea1"></textarea>
  <textarea name="textarea2"></textarea>
</form>

You should use this function in this way:
post_content("http://www.site.com/page.html",2,"textarea1=value1&textarea2=value2")

$nfields=2 because you have two fields (textarea1 and textarea2) ,
$fields_sring = "textarea1=value1&textarea2=value2" because you want to post two variables ( fields values) value1 for the field textarea1 and value2 for the field textarea2, you have to write always "&" between each couple of fieldname-value.

What does this all mean, and for what ?
With this function you will be able to "assimilate" the use of the form and the submit button, and this mean you will be able to get the content of the page www.site.com/pahe.php without using the form, because php can't use a form :)

That's all !