Here is a quote from the Lawnsite FAQ. Maybe it will help you post your image.
"To attach a file to a new post, simply click the [Browse] button at the bottom of the post composition page, and locate the file that you want to attach from your local hard drive.
Only certain types of files may be attached: these are the valid file extensions for files to be attached to this board: htm html gif jpg jpeg png txt zip bmp jpeg doc xls pdf.
After posting, the attachment will show up in the body of your message. To view the contents of the attachment (if it is not already displayed) simply click the filename link that appears next to the attachment icon .
You may also have to resize the file. To do this I used regular old paint and cliked on "file" then "open", browse the files and chose the one you want to use.
Once the image shows up click "image" then click "stretch/skew" and changed the 100% values of strech(there is two) to about 20% and the whole image shrinks right there. Remember to save the file to a name that is easy to find.
Then follow Team Gophers instructions to insert the file to LawnSite.
I tried to post it but I created it with a Printmaster program and that program makes it into a " .biz " file. If you guys can tell me how to change it to a bitmap, j-peg, or something else I will post it. THanks