float random_float ( float number1, [ float number2 ] )
This script returns a random inclusive floating number (i.e. a number with decimals) between the given floating numbers. If number2 is not specified, then a random number between number1 and 0 is returned.
NOTE: There is much debate over the GM's random functionality (whether it's inclusive/exclusive). It's best to assume that the function is inclusive, so that the bottom and top values are possible from the function (even if highly improbable).