write flow condition for a boolean type

[leonvonblut]

Hi,
I create a form with a boolean field, rendered in activiti explorer with a checkbox.
How can I write a flow condition to evaluate that? I always get:

"condition expression returns non-Boolean: $(approved.equals("false")) (java.lang.String)"

the field name and id is "approved"

I tried with:

${approved} - ${!approved}
${approved eq true} - ${approved ed false}
${approved.equals("true")} - ${approved.equals("false")}

Thanks

[leonvonblut]

solved with ${approved == true} - ${approved == false}