414 Request-URI Too Large - MooTools

When  URI is longer than 256 characters, request string produce error.

The difference between GET and POST is that with a GET, you encode all parameters in the URL; with a POST, you send them in the request body, not the URL.  So the URL length limit applies (this is largely the original reason for POST). 

FIX: Replace method get to post

new Request.HTML({
		var req = url:'getData.php',
		method: 'post', 
		data: {'do':'1'}
}).send();