Passing Variables Between ASP Pages using POST
The previous FAQ described how to pass
information from one page to another using the QueryString. To assimilate
variables in the QueryString you can either use a form with METHOD="GET"
or redirect the user to a URL which looks like:
http://www.myserver.com/myasp.asp?var1=hello&var2=world
You can also pass variables using the form METHOD="POST". This has the
effect of "hiding" the parameters passed, since it is done on the
server-side as opposed to having the client pass the information string to
the server (as in the QueryString example above).
A POSTed form looks identical to a GETed form, except instead of
FORM="GET", we put FORM="POST". Here is an
example:
<FORM METHOD="POST" ACTION="myasp.asp">
... HTML here ...
</FORM>
In the file myasp.asp, we read the data the same way we do for QueryString
variables. We just use Request(variablename). For
more information on how to read variables using Request, please read the
previous FAQ.
You may be wondering why anyone would prefer using a GET over a POST or
vice versa. They appear to be identicle. One benefit of a POST is that
you can pass nonstandard characters with less hassle than through the
QueryString. For example, say that you wanted to pass the string:
"Hello my name is ?&!" Well, passing
characters like ?, &, and " " can be cumbersome through the QueryString.
When variables will hold such characters, it is often wiser to put them in
a POSTed FORM as opposed to a GETed one.
Also, in some older browsers there is a limit to the length of the
QueryString. If you need to pass a lot of variables, be sure to
not do it through the QueryString.
