function userAgentChk() {
	var userAgent	= navigator.userAgent;
    if(userAgent.indexOf("MSIE") != -1){
        this.isIE			= true;
		this.agentVer	= userAgent.charAt(userAgent.indexOf("MSIE") + 5);
		if (this.agentVer == 4) this.isIE4 = true;
		else if (this.agentVer == 5) this.isIE5 = true;
		else if (this.agentVer == 6) this.isIE6 = true;
		else if (this.agentVer == 7) this.isIE7 = true;
		else if (this.agentVer == 8) this.isIE8 = true;
    }else if(userAgent.indexOf("Mozilla") != -1 && userAgent.indexOf("compatible") == -1){
        this.isNav = true;
		this.agentVer	= userAgent.charAt(UA.indexOf("Mozilla") + 8);
        if(agentVer == 4 ) this.isNav4 = true;
        else if(agentVer == 5 ) this.isNav5 = true;
        else if(agentVer == 6 ) this.isNav6 = true;
        else if(agentVer == 7 ) this.isNav7 = true;
		else if(agentVer == 8 ) this.isNav8 = true;
    }
}
var uaBc = new userAgentChk();