function compute(form) {

MM=eval(form.month.value)

DD=eval(form.day.value)

YY=eval(form.year.value)

HR=eval(form.hour.value)

MN=eval(form.minute.value)

with (Math) {

HR = HR + (MN / 60);

GGG = 1;

if (YY <= 1585) GGG = 0;

JD = -1 * floor(7 * (floor((MM + 9) / 12) + YY) / 4);

S = 1;

if ((MM - 9)<0) S=-1;

A = abs(MM - 9);

J1 = floor(YY + S * floor(A / 7));

J1 = -1 * floor((floor(J1 / 100) + 1) * 3 / 4);

JD = JD + floor(275 * MM / 9) + DD + (GGG * J1);

JD = JD + 1721027 + 2 * GGG + 367 * YY - 0.5;

JD = JD + (HR / 24);

}

form.result.value = JD;

}