Aflæse indholdet af et givet område

Kode 

<div id="test">Hej</div>

<script type="text/javascript">
	var doContain = function(el,searchstring) {
		if(typeof el == 'string') {
			el = document.getElementById(el);
		}
		
		var s = el.innerHTML ? el.innerHTML : el.value;
		
		if(!searchstring.exec) {
			searchstring = new RegExp(searchstring);
		}

		return searchstring.test(s);
	}
	
	window.onload = function() {
		if(doContain('test','Hej')) {
			alert('s');
		}
		
		// Testing task
		var fn = function() {
			if(doContain('test',new RegExp('Hej'))) {
				alert('Testing each 10th section...');
			}
			setTimeout(fn,10000);
		}
		setTimeout(fn,10000);
	}
</script>