Excel percentage calculation

[Acerpipo]

Hi,

I'm a bit confused and can't find a formula that does;
if I have an amount in A1 and one in B1 and E1 is 100% I want to know how much percent A1 is and how much B1 to have the total of 100%

thx for the help

[shg]

B1: =e1 - a1