Help with JavaScript.

Hi Experts -

I have a JavaScript that worked well in Acrobat. Its function is to tick a checkbox when text is entered into a text field.  I'm trying to apply the JavaScript to do the same thing to another set of boxes (text field and checkbox) in LifeCycle. 

In LifeCycle - I have entered the JavaScript in Script editor, and have 'Show: Validate*'.  Unfortunately it is not working - any help  greatly appreciated. JavaScript from  forum expert kindly supplied is: 

this.getField("checkbox 1").checkThisBox(0, (event.value!=""));

Kind regards

Kevin