Simple function to create a params list type.

Example:
$array = array('first'=>'The first one','second'=>'The second one');

$string = parse_params($array);

//output first=the first one;second=the second one



$string = 'first=the first one;second=the second one';

$array = read_params($string);

//output array('first'=>'The first one','second'=>'The second one')