if (document.all) document.body.onmousedown=new Function("if (event.button==2||event.button==3)alert('Копирование запрещено')")

function showImage(id) {
	document.getElementById(id).style.visibility='visible';
}

function hideImage(id) {
	document.getElementById(id).style.visibility='hidden';
}

function countHeight() {
	var menu_td_height=document.getElementById("menu").offsetHeight;
	var cab_td_height=document.getElementById("cab").offsetHeight;
	var code_td_height=document.getElementById("code").offsetHeight;
	var input_td_height=document.getElementById("input").offsetHeight;
	var main_td_height=document.getElementById("main").offsetHeight;
	var custom_td_height=menu_td_height+cab_td_height+code_td_height+input_td_height;
	if (custom_td_height+34+198<=main_td_height) {
		add_td_height=main_td_height-custom_td_height-198;
	} else {
		add_td_height=34;
	}
	document.getElementById("add").height=add_td_height;
}