World: r4wp

Please read the CGI documentation suggested to you multiple times.

Basically, you create an HTML file and put it on your webserver. 
Let's call it "form.html":


<form action="form.cgi"><input type="text" name="word"><input type="submit"></form>


Then you create a REBOL CGI matching the "action" used above, so 
"form.cgi", and also put it on your webserver:

#!/usr/local/bin/rebol278 -cs
REBOL []
cgi-values: construct decode-cgi system/options/cgi/query-string


;; Now you can access the "word" value submitted via the HTML form
;; as cgi-values/word.

;; Let's echo the value back to the user, as an example:
print rejoin [
  "Content-type: text/html" crlf
  crlf
  cgi-values/word
]

Instead of echoing the value back to the user, you can do whatever 
you want in the CGI. Such as inserting the value in a database.

Where to use throw-on-error function? How differ from DOing a block?

In R2, THROW-ON-ERROR is used for error handling in functions.

In particular, for error handling in functions with the [catch] attribute.

usually as follows:

my-function: func [[catch] x] [throw-on-error [1 / x]]

(notice the [catch] function attribute)

Got it. Thanks a lot.

@Andreas: i could insert data in database ... now i am comparing 
values which user insreted with correct answers ,i got the result 
of that as well but i want show the result to user on web page ,plz 
tell me what should i do?

print ["this is the result:" result]

result is like:[
    ["c" none]
]
[
    ["a" none]
]
[
    ["t" none]
]
[
    ["a" none]
]
[
    ["e" "e"]
]
[
    ["r" none]
]
[
    ["o" "o"]
]
[
    ["a" "a"]
]

i do not want result like this

i want show in neat table

show
 in this case means formatting your own HTML.

in GUI result should not be like blobks, correct?

you mean i should put my gui sfter print

?

then you may need some formatting like:

print "<table>"
foreach row result [print "tr" foreach cell row [print "td" ...

, i.e. print out a HTML table specification

okkkk

err., I meant print "<tr>" in there or print "<td>, etc...

plz tell me how can i use if condition ?

i could get results on web page but there is a problem...in each 
row of table i can see both values(correct and user value )...i want 
use if condition which shows only  the correct result

plzzzzz help

Example:

    print either a < 0 ["a is small"] ["a is big"]

does that help?

or just

    if a < 0 [print "a is small"]

(otherwise nothing is printed)

i need if condition for situation which two values are same

let me try

you mean like this?

    if a =  0 [print "a is zero"]

in my situation what should i write insted of 0?

this is my code:insert db["select data.oneone,data1.oneone from data 
LEFT JOIN data1 ON data.oneone=data1.oneone"]
results: copy db 
if ...

after if what should i write?

You have to tell what are you comparing with what.

i am comparing values of two tables

Yes, but you obtained your RESULT. Now, you are processing the RESULT 
block, I assume?

i want to say if they are same print otherwise alert to user

yes

correct

So, you are doing something like:

foreach record results [
    if first record = second record [...]
]

Is that it?

correcting myself:

foreach record results [
    if (first record) = (second record) [...]
]

yes ,your right ... :) now if i want send meesage to user that value 
is correct or no ...should i use alert?

This is more likely the code you might use:

foreach record results [

    either (first record) = (second record) [print ["they are equal:" 
    first record]] [print ["Alert!"]]
]

ALERT is not meant for CGI, it is a GUI function.

yes

what are you suggesting in GUI?

sorry

CGI

?