Immigrationboards.com

I am applying for indefinite leave to remain on my work permit. The application rewuires documents to proove that I have continiously been in the uk for the past 5 years. Does anyne have suggestions as to what classifies as proof of this?

Thank you

Employer letter
http://www.immigrationboards.com/viewtopic.php?t=51089

Not sure if P60s are mandatory or not as some people had been asked to show them but others were not.