Line Feed in multiline field on stateless form

Line Feed in multiline field on stateless form

I am trying to inset a line feed into a multiline text field on stateless form using script called from a button.   I have seen other posts on this topic but have been unable to get this to work.

When the user click the button, I would like the multiline field to populate with text and input fields seperated by line feeds. 

Following is the script i am trying to run with no success:

RateTextProperty = "Property: " + input.Property + "<br>";
RateTextRate = "Rate: $" + input.Rate + "<br>";
input.Rate_Text = RateTextProperty + RateTextRate;