You can use the Navigator object to retrieve information about the browser that is executing your code. Using this object, you can decide to execute different code for different browsers. It is always a good idea to support different versions of browsers as it helps increase the user base of your Web site.

Here is a simple mechanism to find out which browser and version is running. Function SupportsVendor() returns true if the current instance of browser supports the vendor identified by strVendorName and version identified by strVersion.

 function SupportsVendor(strVendorName, strVersion){ var blnSupportsVendor = false; var blnSupportsVersion = false;  // Check for browser name blnSupportsVendor = (navigator.appName.indexOf(strVendorName) != -1); // if current browser supports the vendor then look for the version if(blnSupportsVendor)  blnSupportsVersion = (navigator.appVersion.indexOf(strVersion) != -1); // return true if current browser supports vendor and the version return (blnSupportsVendor && blnSupportsVersion);}

If you call this function while running Internet Explorer, then you will get true for “Microsoft” (IE4) whereas you will get false for “Netscape”.

 SupportsVendor("Microsoft", "4.");     // returns trueSupportsVendor("Netscape", "4.");    // returns false