Selected Listbox Item to Textbox

I have a UserForm containing a listbox with say 10 items in it. I want to be able to select an item from the list box and have the selected item passed dynamically to a textbox on the same userform.

I have tried writing some code but get errors such as "Compile error: Argument not optional".

Anyone know how to make this work?

Thanks

Can you post the code you tried?

This code would put the selected item from ListBox1 in TexTBox1.

TextBox1.Value = ListBox1.Value