The Mid function returns a substring of
a string argument.
Returns: A string.
Syntax

>>-Mid--(--String--,--StartIndex--+-----------+--)-------------><
'-,--Length-'
Parameters
- String
- Specifies
the string whose substring is to be returned.
- StartIndex
- Specifies the one-indexed character of the string from which the
substring starts. For example, if you specify a start index of 2 for
the string Duluth, the first character of the substring
would be u. You must specify a value greater than
1. If you specify a value greater than the length of the string, the
function returns the empty string.
- Length
- Specifies the length of the substring to return. If you omit this
parameter, the function returns the substring that starts at the character
that StartIndex specifies and ends with the last
character of the string. You cannot specify a negative length.