function document.oncontextmenu()
{
	var _tagName=event.srcElement.tagName;
	if(_tagName && _tagName!="INPUT" && _tagName!="TEXTAREA" || event.srcElement.disabled || document.selection.createRange().text.length==0)
	{
		event.returnValue=false;	
	}
}
function document.onselectstart()
{
	var s=event.srcElement.tagName;
	if(s!="INPUT" && s!="TEXTAREA") event.returnValue=false;
}
function document.ondragstart()
{
	event.returnValue=false;
}
function document.onkeydown()
{
	var presskey;
	presskey=event.keyCode;
	if(event.keyCode=="116" || event.keyCode=="112" || (event.ctrlKey && event.keyCode==82))
	{
		event.keyCode=0;
		event.returnValue=false;
	}
	if(event.ctrlKey)
	{
		if(presskey=="78" || presskey=="65" || presskey=="67" || presskey=="86" || presskey=="66" || presskey=="85" || presskey=="73" || presskey=="68" || presskey=="70" || presskey=="71" || presskey=="80" || presskey=="81" || presskey=="87" || presskey=="84" || presskey=="79")
		{
			event.returnValue=false;
		}
	}
}