Need some advice regarding Tourist Visa. I am in the process of inviting my parents to the USA on a Tourist Visa, I have some questions of the documents required. I think I know what documents I need to send from my side (like bank statement, letter to embassy, employment letter). However I have some questions about the Personal Letter/Reason to return and  Property Valuation from my parents side, I just want to know what Personal Letter should look like, and where/how do I get the property valuation done.  If anyone can provide advice, it will be greatly appreciated. Thanks