PHP input sanitizer?

Question

What are some good PHP html (input) sanitizers?

Preferably, if something is built in - I\'d like to us that.

UPDATE:

Per the request

Answer 1

use

 $input_var=sanitize_input($_POST);

and functions are below, almost sanitize everthing u need

function sanitize($var, $santype = 1){
     if ($santype == 1) {return strip_tags($var);}
     if ($santype == 2) {return htmlentities(strip_tags($var),ENT_QUOTES,'UTF-8');}
     if ($santype == 3) 
     {
      if (!get_magic_quotes_gpc()) {
       return addslashes(htmlentities(strip_tags($var),ENT_QUOTES,'UTF-8'));
      } 
      else {
         return htmlentities(strip_tags($var),ENT_QUOTES,'UTF-8');
      }
     }
    }

---

    function sanitize_input($input,$escape_mysql=false,$sanitize_html=true,
             $sanitize_special_chars=true,$allowable_tags='
')
    {
      unset($input['submit']); //we use 'submit' variable for all of our form

      $input_array = $input;

      //array is not referenced when passed into foreach
      //this is why we create another exact array
      foreach ($input as $key=>$value)
      {
       if(!empty($value))
       {
        $input_array[$key]=strtolower($input_array[$key]);
        //stripslashes added by magic quotes
        if(get_magic_quotes_gpc()){$input_array[$key]=sanitize($input_array[$key]);} 

        if($sanitize_html){$input_array[$key] = strip_tags($input_array[$key],$allowable_tags);}

        if($sanitize_special_chars){$input_array[$key] = htmlspecialchars($input_array[$key]);}    

        if($escape_mysql){$input_array[$key] = mysql_real_escape_string($input_array[$key]);}
       }
      }

      return $input_array;

    }

Remember : it will not sanitize multidimensional array, u need to modify it recursively.