populate list with each new value

[mariec_06]

I have a file with 3 spreadsheet and one called "parameters" with list for data validation purposes.

I would like that each time a new value is entered in column 2 of one of the three other sheets (in my example, the code is under "H&M" sheeet), a macro goes to "parameters", column 5, look if the new value exists in the list, if yes nothing, if no, add the new value, and sort the list alphabetically before going back to initial sheet.

My problem is the .find code to look into "parameters", range E., i get a "type mismatch" error.

Can someone help?