I am planning on making a WAP page to provide a software.
Now i need to find out what mobile phone model the client who logs into my webpage is using so that i can redirect him/her to the appropriate download link.
This is similar to what opera does on their opera mini site. When you log in it finds out your model and sends you to the link
How can i add this to my site.
What are you using to develop your site? The solution would depend on that.
Here's an article that has some information on what approach you might take, using HTTP headers and user agent profiles
There are a number of solutions for determining mobile device, based on the UserAgent making the request. (Some solutions use other factors as well.)
Try looking at:
The technology you are using to create your pages will also affect which of the above is the best solution for you.
A great website with some tutorials is mobiforge.com (the people behind device atlas), also plenty of true open source software at wurfl
Use http://51degrees.codeplex.com/. It is an ASP.NET open source module which detects mobile devices and provides auto redirection to mobile optimized pages when request is coming from mobile device. It makes use of WURFL mobile device database. For redirection there is no need to modify existing ASP.NET web application pages.