gform_redirect.php

<?php

	add_filter('gform_pre_submission_filter_2', 'custom_redirect_url');
		function custom_redirect_url($form){
			$condition = RGForms::post('input_3');
			if(!$condition)
			return $form;

		    $form['confirmation']['type'] = 'redirect';
			switch($condition){
			case 'pdf2image':
			$form['confirmation']['url'] = 'http://www.pdf2image.com';
			break;
			case 'pdf2picture':
			$form['confirmation']['url'] = 'http://www.pdf2picture.com';
			break;
			case 'pdf2cad':
			$form['confirmation']['url'] = 'http://www.pdf2cad.com';
			break;
			case 'pdf2cadMac':
			$form['confirmation']['url'] = 'http://www.pdf2cad.com';
			break;
			case 'PDFFLY':
			$form['confirmation']['url'] = 'http://www.pdf-fly.com';
			break;
			case 'METAFLY':
			$form['confirmation']['url'] = 'http://www.visual-integrity.com';
			break;
			}
		return $form;
		}

?>