<?php

$html = "the string";

preg_match_all('#<([\w]+)[^>]*>#', $html, $tags);
for($i = 0; $i < count($tags); $i++) {
	foreach($tags[$i] as $tag) {
		if(!strstr($tag,'input')) continue;
		$tag = preg_replace(array('#^<#','#>$#'),'',$tag);
		preg_match_all('/(\w+)((\s*=\s*".*?")|(\s*=\s*\'.*?\')|(\s*=\s*\w+)|())/s', $tag, $matches, PREG_PATTERN_ORDER);

		if(count($matches[3]) > 1) {
			print_r($matches[3]);
		}
	}
}

?>