Preventing interpreting variable as TCL

For anyone who cares, the solution to this was to add "--" after the switch statement, to ensure it parses the next item as the test value rather than one of the command switches:

switch -- [string tolower [lindex [split ${parameter} "="] 0]] {

hoolio's test didn't pick it up, because it was a problem with the switch command syntax, which he didn't use in his test.

Joe's suggestion is not correct: the {curly braces} protect the variable name, not the variable contents.

Thanks for your suggestions.