If Statements (Nested??)

I am trying to accomplish the following in a Microsoft Access 2007 QUERY. I
want to evaluate a field called "Cost Type" for the following values and then
populate a new field (E1) with a value based on the Cost Type.

For example

If Cost Type = L, populate E1 with 1405
If Cost Type = M, populate E1 with 1410
If Cost Type = S, populate E1 with 1480
If Cost Type = G, populate E1 with 1495

Then.....I want to evaluate a different field (Pay Item) for the following
conditions and place a static value in the E1 field...and..these values a

If Pay Item = 955000, populate E1 with 1490
If Pay Item = 955300, populate E1 with 1491
If Pay Item = 955200, populate E1 with 1492
If Pay Item = 955100, populate E1 with 1493

Is there any way to combine these conditions (evalutating 2 fields) into 1
statement

Thank you

Warren Phillips