Before switching to Design view, the HTML Designer looks for any Active Server Pages (ASP) markup embedded within certain HTML tags. If such ASP script is not properly quoted, the HTML Designer displays the error message above and prevents you from switching to Design view.
To correct this error
Example
The ASP markup within the OPTION tag below reproduces this error message and prevents you from switching to Design view:
<SELECT>
<OPTION value="<%=OptionValue1%>">Option 1</OPTION>
</SELECT>
To work around this problem, replace the <OPTION>
markup above with the embedded markup below, quoted within Response.Write commands:
<SELECT>
<%
...Response.Write "<SELECT>"
...Response.Write "<OPTION value='<%=OptionValue1%>'>Option 1</OPTION>"
...Response.Write "</SELECT>"
%>
</SELECT>
This enables you to switch to Design view. However, the <OPTION>
element created by the Response.Write command will not appear there.