validating data

[rethish]

I am confused of validating some of the fields such as email_id ,web address in my project.These fields should omly accept the standard format (for eg: aaaa@aaa.com, www.ddd.com). How can i do this? I m a biginner in mac programming . I use xcode 3.1 , I B 3.1 and objective-C for programming . Please help me with examples to overcome this problem .

 

 

thank you.