Generate random MIN and MAX value from a range of values

Hi All,

 I would like to know if there is any efficient way to generate a random min and max value from a range of  values?

i have a range VAL1 to VAL2... I need to generate a min_val and max_value within this range such that min_val >=VAL1 and max_val>min_val and max_val<=VAL2 

I am not able to use a variable in the keep constraint.

keep MIN_VAL  in [VAL1.. VAL2]

keep MAX_VAL in [MIN_VAL  .. VAL2] -- NOT POSSIBLE

 So is there any work around without using 'gen' inside while? 

Thank you !!!

Cheers,

Bharath.