Hi,
I think you might be better of with another approach, with this approach the user will have the same trouble if they save the form and open it later.
Try change the initialise script to;
this.format.picture.value = "null{________________________________\r\n________________________________\r\n________________________________\r\n________________________________}";
Then you will be able to remove the code in the enter and exit events totally.
The code above sets the null display pattern, which means it will only appear if the field has no value. Normally you can enter this in the the display pattern dialog but that doesn't allow you to enter the carridge-return/line-feed characters.
Regards
Bruce