This is a test of code with curly brackets which can cause problems since they are used by Confluence macros. However, in this exammple they appear to work find.
<input name="Subject" size="40" value="<% $ARGS{Subject} %>" /><br />
Here's the same code with curly brackets escaped. The escapes show up which is not very useful.
<input name="Subject" size="40" value="<% $ARGS\{Subject\} %>" /><br />