Nested if in Array

Good day,

I have attached my speadsheet to simpfly my describtion of my troubles. On the Team1 tab I have a formula entered in cell C4 that should work but it doesn't. What I am trying to do is lookup the Employee's ID and Day of the Week on the Time Off tab, and if it finds both for that pictular day of the week then return and "A" for absent and null string if it finds nothing. My current formula is working for the first cell but it isn't for the ones below.
Any help would be great.

Chris