function lib_bwcheck(){ 
this.ver=navigator.appVersion; 
this.agent=navigator.userAgent
this.dom=document.getElementById?1:0
this.win = (navigator.appVersion.indexOf("Win")>0);
this.xwin = (navigator.appVersion.indexOf("X11")>0);
this.ie5=(this.ver.indexOf("MSIE 5")>-1 && this.dom)?1:0;
this.ie6=(this.ver.indexOf("MSIE 6")>-1 && this.dom)?1:0;
this.ie4=(document.all && !this.dom)?1:0;
this.ie=this.ie4||this.ie5||this.ie6
this.mac=this.agent.indexOf("Mac")>-1
this.opera5=this.agent.indexOf("Opera 5")>-1
this.ns6=(this.dom && parseInt(this.ver) >= 5) ?1:0; 
this.ns4=(document.layers && !this.dom)?1:0;
this.bw=(this.ie6 || this.ie5 || this.ie4 || this.ns4 || this.ns6 || this.opera5 || this.dom||false);
this.width = null;
this.height = null;
return this
}
function getObjectById( ID ) {
var bw = new lib_bwcheck();
if (bw.ns6) return document.getElementById(ID);
else if (bw.ns) return document.layers[ID];
else return document.all[ID];
}