Case sensitivity on Solaris

I have been struggling with a shell script on Solaris.
The problem was the case sensitivity in unix. The shell script I made is expecting 4 parameters and I wanted the script to treat them case insensitive.
I had an example script from an HP Unix environment, but apparently the syntax on Solaris Unix is a little bit different...
On HP I used the following...

ENVIRONMENT=$(echo $IDENT tr "[a-z]" "[A-Z]")

but that didn't work on Solaris...
But I found the translation on google..

ENVIRONMENT=`echo ${IDENT} tr '[a-z]' '[A-Z]'`