Warning: Undefined offset....?

Et All: I am trying to set up the Lucid Calendar App that can be found on Freshmeat.com. Everything works but I keep getting this error message at the top of the calendar table: Warning: Undefined offset: 1 in ./api/cal.api on line 534 Actually there are 34 of them. This is what is at line 534: for( $i=0 ; $i < $num_of_rows*7 ; $i++ ){ if( $i==0 ){ echo "<tr>\n"; What is an Undefined Offset? Voll Corn Site Admin/Developer Ur.mot.com Global University Relations, Motorola Austin, Tx