Nest If Statements Dependent on Multiple Cells

Could someone give me the right formula for this? I cant seem to make nested IF statements work right and my experience with formulas is minimal. (Coding nonexistent)

I have 4 columns in which dates are entered. I have a fifth column for "Status".

SO I would like a formula that says:
If A1 has a value (date) then E1="Requested".
But if B1 has a value then ignore A1 statement and E1="Accepted".
But if C1 has a value then ignore A1 & B1 statements and E1="Rejected".
But if D1 has a value then ignore A1, B1 & C1 statements and E1="Completed".
And if no value in A1:D1 then E1=(blank cell)

(A1) Requested
(B1) Accepted
(C1) Rejected
(D1) Completed
(E1) Status

The columns in the attached spreadsheet to correspond with the above are K,L,M,N (A-D) and J (E)