Fix typo.

ISHelp/isxfunc.xml

@@ -2672,7 +2672,7 @@ Page := CreateOutputMsgMemoPage(wpWelcome,
       </function>
       <function>
         <name>CreateExtractionPage</name>
-        <prototype>function CreateExtractionPage(const ACaption, ADescription: String; const OnExtractionProgress: TOnExtractionProgress): ExtractionWizardPage;</prototype>
+        <prototype>function CreateExtractionPage(const ACaption, ADescription: String; const OnExtractionProgress: TOnExtractionProgress): TExtractionWizardPage;</prototype>
         <description><p>Creates a wizard page to extract 7-Zip archives and show progress.</p>
 <p>Set OnExtractionProgress to a function to be informed of progress, or <tt>nil</tt> otherwise.</p>    
 <p>Unlike the other types of wizard pages, progress pages are not displayed as part of the normal page sequence (note that there is no <tt>AfterID</tt> parameter). A progress page can only be displayed programmatically by calling its <tt>Show</tt> method.</p></description>