Sending product value instead of label to paypal

this is what i added to the function.php. 10 is the form ID field.

add_filter('gform_paypal_query', 'update_paypal_query', 10, 3);
function update_paypal_query($query_string, $form, $entry){
	parse_str($query_string, $qs_param); //put PayPal querystring into an array
	if (is_array($qs_param)){
		$field = RGFormsModel::get_field($form, 10); //get form field, the 2nd parameter is the field id
		$value = RGFormsModel::get_lead_field_value($entry,$field); //get the value of the field
		//product fields are pipe-delimited, the value will be the first item in the string
		if (!empty($value)){
			$ary_values = explode("|",$value); //put the values into an array and grab out the first item [0]
			$qs_param["item_name_1"] = $ary_values[0]; //replace the item name in the querystring with the value, the "1" is the field id
			$query_string = "&" . http_build_query($qs_param); //put array back into querystring form
		}
	}

	return $query_string;
}