Advice on Regression Model Using PROC GLM in SAS

Hi Everyone, thanks for your insight on this.

I will try to explain my data set as well as possible.
One of the models I am running on my data set includes have 2 continuous IV's predicting 1 continuous DV. However each of these IV's were derived multiple time under differing crossed conditions for each participant, making my data nested. For this particular model i don't care about which conditions, but the nesting is still reflected in my data.

for example

1 45 67 100
1 22 55 29
1 45 78 67
2 67 35 67
2 34 44 99
2 44 44 29

right now, my model looks something like this

proc glm
DV = IV1|IV2

my question is --- how do I get the error term not include all the entire pooled error (right now the term, and respective DF are reflecting all of the shared variance, but I need it to reflect specific effects in the model). Do i need to include subject ID somewhere in the model?