ASP Forms and User Input
The Request.QueryString and Request.Form commands may be used to retrieve information from forms, like
user input.
Examples
A form with
method="get"
How to interact with the user, with the Request.QueryString command.
A form with
method="post"
How to interact with the user, with the Request.Form command.
A form with radio buttons
How to interact with the user, through radio buttons, with the Request.Form command.
User Input
The Request object may be used to retrieve user information from forms.
Form example:
<form method="get" action="simpleform.asp">
First Name: <input type="text" name="fname" />
<br />
Last Name: <input type="text" name="lname" />
<br /><br />
<input type="submit" value="Submit" />
</form>
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User input can be retrieved in two ways: With Request.QueryString or Request.Form.
Request.QueryString
The Request.QueryString
command is used to collect values in a form with method="get". Information sent from a form with the GET method is visible to everyone
(it will be displayed in the browser's address bar) and has limits on the amount
of information to send.
If a user typed "Bill" and "Gates" in the form example
above, the URL sent to the server would look like
this:
http://www.w3schools.com/simpleform.asp?fname=Bill&lname=Gates
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Assume that the ASP file "simpleform.asp" contains the following script:
<body>
Welcome
<%
response.write(request.querystring("fname"))
response.write(" " & request.querystring("lname"))
%>
</body>
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The browser will display the following in the body of the document:
Request.Form
The Request.Form
command is used to collect values in a form with method="post". Information sent from a form with the POST method
is invisible to others and has no limits on the amount of information to send.
If a user typed "Bill" and "Gates" in the form example
above, the URL sent to the server would look like
this:
http://www.w3schools.com/simpleform.asp
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Assume that the ASP file "simpleform.asp" contains the following script:
<body>
Welcome
<%
response.write(request.form("fname"))
response.write(" " & request.form("lname"))
%>
</body>
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The browser will display the following in the body of the document:
Form Validation
User input should be validated on the browser whenever possible (by client scripts).
Browser validation is faster and you reduce the server load.
You should consider using server validation if the user input will be
inserted into a database. A good way to validate a form on the server is to post
the form to itself, instead of jumping to a different page. The user will then
get the error messages on the same page as the form. This makes it easier to
discover the error.
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