you can use another if statement as one of your arguments in your if statement

eg

=if( [logicaltest1] , "test 1 true" , if ( [logicaltest2] , "test 2 true" ,
"neither true" ) )
In your case:
=if(A1=100,100,if(A1="",0,50))

"Patience" wrote:

Is there any way to write a formula that will examine the cell contents, and
return one of three different values?
I want the formula to look at column A, and if column A value is less than
100, return "50", if it's 100 or more, to return "100", and if it's null or
0, to return "0."
I'm using Office 2003
Thanks,