IF.EXE - Main script control function.

Use: IF xxxx cond yyyy GOTO zzzz

Where xxxx is an envar

cond is "=" or “<>” for maths/strings or "<" or ">" for maths only.

yyyy = an immediate hex value, the value of another Envar in brackets or a 4-char string in quotes "yyyy"

zzzz = a 4 char label

EG: IF ERR > 0 GOTO FAIL
IF STR = “THIS” GOTO THAT