function verifyCompatibleBrowser(){ 
    this.ver=navigator.appVersion 
    this.dom=document.getElementById?1:0 
    this.ie5=(this.ver.indexOf("MSIE 5")>-1 && this.dom)?1:0; 
    this.ie4=(document.all && !this.dom)?1:0; 
    this.ie5p=(document.all && this.dom)?1:0; 
    this.ns5=(this.dom && parseInt(this.ver) >= 5) ?1:0; 
 
    this.ns4=(document.layers && !this.dom)?1:0; 
    this.bw=(this.ie5 || this.ie4 || this.ns4 || this.ns5) 
    return this 
} 

bw=new verifyCompatibleBrowser();