禁止网页复制js代码

<script id="wpcp_disable_selection" type="text/javascript">
//<![CDATA[
var image_save_msg='You Can Not Save images!';
	var no_menu_msg='Context Menu disabled!';
	var smessage = "";

function disableEnterKey(e)
{
	if (e.ctrlKey){
     var key;
     if(window.event)
          key = window.event.keyCode;     //IE
     else
          key = e.which;     //firefox (97)
    //if (key != 17) alert(key);
     if (key == 97 || key == 65 || key == 67 || key == 99 || key == 88 || key == 120 || key == 26 || key == 85  || key == 86 || key == 83 || key == 43)
     {
          show_wpcp_message('You are not allowed to copy content or view source');
          return false;
     }else
     	return true;
     }
}

function disable_copy(e)
{
	var elemtype = e.target.nodeName;
	var isSafari = /Safari/.test(navigator.userAgent) && /Apple Computer/.test(navigator.vendor);
	elemtype = elemtype.toUpperCase();
	var checker_IMG = '';
	if (elemtype == "IMG" && checker_IMG == 'checked' && e.detail >= 2) {show_wpcp_message(alertMsg_IMG);return false;}
	if (elemtype != "TEXT" && elemtype != "TEXTAREA" && elemtype != "INPUT" && elemtype != "PASSWORD" && elemtype != "SELECT" && elemtype != "OPTION" && elemtype != "EMBED")
	{
		if (smessage !== "" && e.detail == 2)
			show_wpcp_message(smessage);

		if (isSafari)
			return true;
		else
			return false;
	}
}
function disable_copy_ie()
{
	var elemtype = window.event.srcElement.nodeName;
	elemtype = elemtype.toUpperCase();
	if (elemtype == "IMG") {show_wpcp_message(alertMsg_IMG);return false;}
	if (elemtype != "TEXT" && elemtype != "TEXTAREA" && elemtype != "INPUT" && elemtype != "PASSWORD" && elemtype != "SELECT" && elemtype != "OPTION" && elemtype != "EMBED")
	{
		//alert(navigator.userAgent.indexOf('MSIE'));
			//if (smessage !== "") show_wpcp_message(smessage);
		return false;
	}
}
function reEnable()
{
	return true;
}
document.onkeydown = disableEnterKey;
document.onselectstart = disable_copy_ie;
if(navigator.userAgent.indexOf('MSIE')==-1)
{
	document.onmousedown = disable_copy;
	document.onclick = reEnable;
}
function disableSelection(target)
{
    //For IE This code will work
    if (typeof target.onselectstart!="undefined")
    target.onselectstart = disable_copy_ie;

    //For Firefox This code will work
    else if (typeof target.style.MozUserSelect!="undefined")
    {target.style.MozUserSelect="none";}

    //All other  (ie: Opera) This code will work
    else
    target.onmousedown=function(){return false}
    target.style.cursor = "default";
}
//Calling the JS function directly just after body load
window.onload = function(){disableSelection(document.body);};
//]]>
</script>