function clickButton(e, buttonid){ 
     var bt = document.getElementById(buttonid); 
     if (typeof bt == 'object'){ 
           if(navigator.appName.indexOf("Netscape")>(-1)){ 
                 if (e.keyCode == 13){ 
                       bt.click(); 
                       return false; 
                 } 
           } 
           if (navigator.appName.indexOf("Microsoft Internet Explorer")>(-1)){ 
                 if (event.keyCode == 13){ 
                       bt.click(); 
                       return false; 
                 } 
           } 
     }
}