Please help with access expression

Hello,

I was hoping someone could assist with the following expression in
access that combines the Left function and Len function:

I have column called ID, which has about 700,000 records and each ID
can be anywhere from 7 to 10 characters; however, I all IDs to have
only 7 characters and this means removing characters that are greater
than 7. For example, smith09 is fine, but smith09990 would need to
reduced to smith09. Basically, i need an expression that will check
every ID and, if ID 7 characters, use the left function to cut it to
7 characters.
Please let me know if you need more information:

I provided a table below of what I need. There are over 700,000
records in this table:


ID: expression

Smith09 Ok
Smith0978 Smith09