function add5( x, y, z, w, u ) {
	return x + y + z + w + u;
}
Computes the sum of five double-precision floating-point numbers.

@param {number} x - first input value
@param {number} y - second input value
@param {number} z - third input value
@param {number} w - fourth input value
@param {number} u - fifth input value
@returns {number} sum

@example
var v = add5( -1.0, 5.0, 2.0, -3.0, 4.0 );
// returns 7.0

@example
var v = add5( 2.0, 5.0, 2.0, -3.0, 4.0 );
// returns 10.0

@example
var v = add5( 0.0, 5.0, 2.0, -3.0, 4.0 );
// returns 8.0

@example
var v = add5( -0.0, 0.0, -0.0, -0.0, -0.0 );
// returns 0.0

@example
var v = add5( NaN, NaN, NaN, NaN, NaN );
// returns NaN