have somebody any idea ,about which is more powerful between PHP and ASP.net ?,which is more relyable between those programming language,why i ask like that ?,when i learn ASP.net, it is more complicated and harder than PHP,if PHP is easier than ASP.net, why do lots of people use ASP.net. and why ASP.net seems to be a sensational software for developing web application,i'd like an information about this.

It is rather hard to define "simpler". In some cases, simplicity brings limited features. The reason many people may go with ASP.NET is that it has lots of features out of the box for working with databases or various pre-built controls and now (with ASP.NET 3.5) fully integrated ajax support with a very comprehensive client-side library. I don't know what kind of comparable features PHP or other web frameworks have (Rails, jsp, etc). Hopefully someone else can offer a better comparison than me.

I found this, haven't looked at it much but it might be useful for you.
http://www.oracle.com/technology/pub...hull_php2.html

-Peter