It is not possible to dynamically modify values in a page when clicking in a checkbox. As an alternative, you could try using a <choiceParameterGroup> with two options, each of them with a different port:
<choiceParameterGroup> <name>protocol</name> <title>Protocol</title> <description>Protocol</description> <value>http</value> <parameterList> <parameterGroup> <name>http</name> <explanation>HTTP</explanation> <parameterList> <stringParameter> <name>httpPort</name> <description>Port</description> <value>80</value> </stringParameter> </parameterList> </parameterGroup> <parameterGroup> <name>https</name> <explanation>HTTPS</explanation> <parameterList> <stringParameter> <name>httpsPort</name> <description>Port</description> <value>443</value> </stringParameter> </parameterList> </parameterGroup> </parameterList> </choiceParameterGroup>
In the example, both options allow configuring the port but you could use a <labelParameter> to display a read-only version. It also uses parameter groups as options, in case you want to add more settings there but you could also just use the string parameters:
<choiceParameterGroup> <name>protocol</name> <title>Protocol</title> <description>Protocol</description> <value>http</value> <parameterList> <stringParameter> <name>httpPort</name> <description>HTTP Port</description> <value>80</value> </stringParameter> <stringParameter> <name>httpsPort</name> <description>HTTPS Port</description> <value>443</value> </stringParameter> </parameterList> </choiceParameterGroup>
You can find additional information about the usage of the <choiceParameterGroup> here
