MACROMEDIA COLFUSION MX 7-CFML Reference page 671

<p>During the first time through this template, the variable "form.myString"
has not yet been defined, so we do not try to evaluate it.
</cfif>
<form action="#CGI.Script_Name" method="POST">
<input type="Text" name="MyString" value="My sample value">
<input type="Submit" name="">
</form>
IsDefined 671