Help with iRule

Hi,

 

I am a beginner with writing iRules and it would be great to get some tips on where to start.

 

My requirements are i need to do a health check against a web server by doing HTTP get on a file (blah.pac) and checking for a string within the file. If the string is there then the server is available if not then bring the server down.

 

 

Any help would be greatly appreciated.

 

 

Regades,

 

David