function check_browser0(){
//			alert(navigator.userAgent);
        if ((navigator.userAgent.indexOf ("MSIE") != -1)){
            if(document.getElementById('login_block')){
                document.getElementById('login_block').style.marginTop='-5px';
            }
			
        }else if ((navigator.userAgent.indexOf ("Firefox") != -1)){
            if(document.getElementById('login_block')){
                document.getElementById('login_block').style.marginTop='1px';
            }
        }else{
            if(document.getElementById('login_block')){
                document.getElementById('login_block').style.marginTop='0px';
            }
        }
    }