Excellent !! its working fine now.
But there is one small problem, If there is an error in field one and also field two then I should have only error to be printed as "102". but not both "102" and "104" to be printed, basing on the serial order of fields like field1, field2. Also can I use the error value in a variable so that I can use it for different purpose in my script(outside awk)?

Here is the script:
#!/bin/ksh

awk -F"," 'NR>=3 {
if (length($2)!= 8 || $2 ~ /[^0-9]/ || $2 ~ /^ *$/ ) {var1="102"}
if ( $4 ~ /^ *$/ ) {var1="104"}
{printf var1}
printf("\n")
}' $1


The output:


102
104