overrideMimeType alternative for IE

[kuntul]

This is a question that never has a proper answer, i have search the net many times and i couldnt find a solution.\[code\]xhr.open("GET", fullurl, true);if(xhr.overrideMimeType) xhr.overrideMimeType("text/html; charset=ISO-8859-1");xhr.send(null);xhr.onreadystatechange = function(){ if(xhr.readyState == 4){if(xhr.status == 200) alert(xhr.responseText);\[/code\]It works for firefox, chrome. My responseText will return char like R