function needed

["Thomas Z." <thomas.zm@xxxx>]

Hello,
 
Who can help me?
I need a simple function. I have 2 or morevalue's 
and i need the lowest of this value's.
 
Example:

S1 = 500<FONT 
face="Courier New" size=1>; S2 = <FONT face="Courier New" color=#ff00ff 
size=1>1000;
Graph0 = <FONT 
face="Courier New" color=#0000ff size=1>LLV<FONT face="Courier New" 
size=1>(S1 OR S2,1);
But i see no graph.
Hope, that anyone can 
help me
<FONT face=Arial 
size=2>Thomas