function getPageCharset(){   
    var charSet = "";   
    var oType = getBrowser();   
    switch(oType){   
       case "IE":   
            charSet = document.charset;   
            break;   
        case "FIREFOX":   
            charSet = document.characterSet;   
            break; 
        default: 
            charSet = document.characterSet;  
            break;   
    }   
    return charSet;   
}   
function getBrowser(){   
    var oType = "";   
    if(navigator.userAgent.indexOf("MSIE")!=-1){   
        oType="IE";   
    }else if(navigator.userAgent.indexOf("Firefox")!=-1){   
        oType="FIREFOX";   
    }   
    return oType;   
}   

if(getPageCharset()!='utf-8' && getPageCharset()!='UTF-8'){
window.location = window.location;
}