what is " XILINX environment variable " ?

[omidsht]

Hi , I have installed ISE10.1 and I have MATLAB R2008a.
then when I run SELECT MATLAB vesion for Sytem Generator from ise10.1 - dsp tools from start menu , in the apeared window i see my matlab , then when i tick it and select okay , it says :
"error - XILINX environment variable is not set " !
what is " XILINX environment variable " ? how should i set it ?

thanks in advanced

 

[M!k]

**broken link removed**

 

[gooofy871]

thanks..