Exclude .asp from url rewrite

[experience]

I've installed a new wordpress website

In order to get friendly links on the website i have added the following code to my web.config - however my existing .aspx page wont post unless i remove it

When i click the submit button the page reloads

Any idea how to fix it?

    <rewrite>
      <rules>
        <rule name="wordpress" patternSyntax="Wildcard">
          <match url="*" />
          <conditions>
            <add input="{REQUEST_FILENAME}" matchType="IsFile" negate="true" />
            <add input="{REQUEST_FILENAME}" matchType="IsDirectory" negate="true" />
          </conditions>
          <action type="Rewrite" url="index.php" />
        </rule>
      </rules>
    </rewrite>