Andrew - to test for equality (in your condition) you need to use two equal signs as
currents == 413
You use one equal sign for assignment as in
x = 42;
Though is this condition really what you want? Presumably, you have defined your currentsum as 413 before you enter the while loop (else the condition would never be satisfied) and you must be doing something more within this loop than what you have shown us.
Note that sum(k), where k is your array, finds the sum of all elements in your array...which is 413 and so your while condition is always satisfied and you will never exit the while loop.
You may want to provide more details about what you are attempting to do. Are you just trying to add up all consecutive numbers within an array until at least 413 is reached? Please clarify.
