director loan agreement

Hi Guys

I am doing the business by director's loan. so i think I need a directors loan agreement. However, my friend told me that I need find a solicitor to make a agreement, the cost will be 500 pounds plus VAT, so expensive! my question is: is it necessary to find a solicitor to help me to do that agreement？or can I just copy the agreement sample to do it by myself?

Thanks very much!