I have created one web application in my http://localhost and also in http://ajay where ajay is my system name.

but when I am trying to debug or run application it pop up one message box saying

that the web application u r trying to access is not available in ur web server, plz hit the refresh tab in ur project folder.

I have checked my IIS my application folder is there .

this is first time I m creating application there before that I have created all app. in File System 

can anyone tell me why it is happening.

thanks in advance. 

Go to IIS management Console and convert that virtual directory to Application.

To Do that...

1) right click on the virtual folder in IIIS console

2) select properties

3) Inside General Tab there will be a button named Create. Click that.

After all this make sure that in your web.config file debug is set to true.

Hope this helps.

If this post has helped you solve your problem, please mark it as an answer.

I am not getting u.

I have opened my  inetmgr(IIS) and there under default website folder  my application is available.

when I right click and go to property there is no button like Create

I am using VS2005 and window xp professional. 

1. inetmgr-->Application Name would be active.

2. check LOcal path. it would be C:\Inetpub\wwwroot\yourAppName

3. in document tab add your deafult page on first priority.

4. Directory Security--> Edit--> Check for Integrated Windows authentication.

5. ASP.net tab--> file location would be-->C:\Inetpub\wwwroot\yourAppName\web.config

Click OK and refresh and try again.

I have installed  IIS again  in my pc and all things working perfectly.