Write a Program to Enter any two numbers and print average number

QBASIC Program to get any two numbers from the user and print the average. 

CLS
INPUT "Enter First Number: "; a
INPUT "Enter Second Number: "; b 
av=(a+b)/2
PRINT "Average = "; av 
END

Using SUB Procedure

DECLARE SUB avrg(a,b) 
INPUT "Enter First Number: "; a
INPUT "Enter Second Number: "; b 
CALL avrg(a,b) 

END

SUB avrg(a,b)
av=(a+b)/2
PRINT "Average = "; av 
END SUB 

Using FUNCTION Procedure

DECLARE FUNCTION avrg(a,b)
CLS
INPUT "Enter First Number: "; a
INPUT "Enter Second Number: "; b 
av = avrg(a,b)
PRINT "Average = "; av 
END

FUNCTION avrg(a,b)
av = (a+b)/2
sum = av
END FUNCTION