awk - Beginners Question

Shell Programming and Scripting
1

I have my inputfile in the following format :

From:sdhfhg
dsfhsdjfjdsfh
dsfjdjshjsd
djfhsdjfjsdhjds
Error Description
<aa.aa.aa.aa.aa.aa>
From:ksljfsdhfjh
djfdsjkf
sdjwoquk
dsfsdfj
Error Description
<dd.dd.dd.dd.dd>
I want to read the lines from tag 'From:' thrul <aa.aa.aa.aa.aa.aa> similarly for the next block. Next I want to read the Error Description and assign an codenumber to it.

I am using the following code :

#this is my first awk program
BEGIN {errorcode=0}

/From/ {take actions}
      #Read until next 'From'
       {while!(^/<[a-z]/)
         if (/ErrorDesc1/) print "01"
         else if(/ErrorDesc2/) print "02"
         else if(/ErrorDesc3l/) print "03"}

       {if(errorcode != 01 && errorcode != 02 && errorcode != 03) print "04"}

I get the following error :
The error context is
>>> {while! <<< (^/<[a-z])
awk: The statement cannot be correctly parsed.
The source line is 13.

Can someone guide...I am new to awk programming.

2

Something to start with:

BEGIN {errorcode=0}

/From/
      #Read until next 'From'
       {
       while( /^<[a-z]+/ !~ $0 )
         {
         if (match ($0,/Error Description/))
            print "01"
         else if (match ($0,/ErrorDesc2/))
            print "02"
         else if(match ($0,/ErrorDesc31/))
            print "03"
         next
         }
       }

       END{
       if(errorcode != 01 && errorcode != 02 && errorcode != 03) print "04"
       }