What is the correct way to do this type of conversion?

What im doing is getting information from an XML file, converting that text into a float with parseFloat. Trying to pass this number directly into a yield waitForSeconds(); call gives me the following error:

Cannot convert 'callable(int) as float' to 'float'.

What am i doing wrong here? Simple mistake? Thanks for your time!

EDIT- here you go, scripts to follow.

xml get data script :

var waitTimeNext: float;

function start()
{
        var tempWaitTimeNext: String = stepNode.GetValue("wait>2>_text");
        tempStepObj.waitTimeNext = parseFloat(tempWaitTimeNext);
}

script with yield :

        var c : float = (lessonDataScript.getStepWaitTimeNext);
        yield WaitForSeconds (c);

What is "getStepWaitTimeNext?" Is that a function that returns the value in "tempStepObj.waitTimeNext?" If so, you need to put parentheses after it to call it. Otherwise, you're trying to put a callable (or function definition) into that float value, c.