FIELDS IN SEQUENCE IN ARCGIS 

THE CODE FOR THE THIRD METHOD IS THE FOLLOWING:
rec = 0
def autoIncrement ():
global rec
pStart = 1
pInterval = 1
if (rec == 0):
rec = pStart
else:
rec = rec + pInterval
return rec
NOTE: THE THIRD METHOD CAN BE USED WHEN THE INTERVALS OF THE INFORMATION ARE 2 OR 3 OR ANY OTHER INTERVAL.