can ayone put a value on my poster If i knew how to upload a picture it would be easier! i bought it in field of dreams in vegas so it has authenticity, It is signed by mark hamill carrie fisher and harrisson ford i have researched it and have been told it is the most sought-after 1977 artworkk.The guy in the shop told me it was and original poster but the dimensions dont match so i think its a print,if you can tell me how to put a picture on here i would be grateful for any help,,,,,someone could have a bargain!!!!!!