i make a form that can select a car type by combo box and value list all car type in it , i want to have the car logo on my report .
it means when i select BMW in car selection in my form , i see the car logo in my report when i want to print it .
I am going back to the original problem statement. I will tell you as clearly as I can what I would do, which doesn't mean I'm exactly right and any of the others are wrong. This is just MY take on it.
To do this, I would include some kind of code or index in the combo box to correspond to the car type that was selected. The combo box can have multiple columns. One of them should be the code. When you store the record about the car, include the code that you extract from the correct column of the combo box, regardless of any name that shows up in another column.
This code should tie back to a table that contains a hyperlink to the logo / image that you want displayed. Or just a file spec. It is possible that you would store this spec as a short text field in the table that drives the combo box. The code would probably be the prime key of that table.
The format of that file specification will depend on details of your setup, but at the minimum would be either the drive letter, path, name, and type, or the UNC network path, name, and type of the image file. Depending on how you are sharing this, the UNC choice might be better. You DON'T CARE if this is more than 100 characters. The table will only list each path once based on the code, which should be the prime key of the table.
Now in the report, in the detail section where this car record would be displayed, you have the a recordset that shows you specific details including the selection code. You can either use a JOIN in the query that defines the report's .RecordSource OR you could have a DLookup to recover the file spec. (I would use a JOIN myself.)
On the report in the detail section, you need to have an image control. In the detail section's ON FORMAT routine, you need a small amount of code that will look up that spec (if not JOINed) or just pick up the spec from the recordset and load it to the image controls .Picture property. You might have to "diddle" the other image properties dealing with aspect ratios, sizes, etc., but that is how I would approach the problem.
I didn't tell you in code. I used my words so that you could try to make sense of it. Sometimes it isn't what you say but how you say it.