for the error message, delete the code at 897:
you do not have a recordset named "Pet_Reg" on the page, thus the error is occurring trying to destroy it.
If the image upload is working for some, but not for others there are a few possibilities:
a) On slower connections, submitting the image may exceed the php max_execution_time setting
b) uploading larger files may exceed the post_max_size setting
see the following page for information on PHP.ini settings that can effect upload: