Question

This question was answered. But stackoverflow will not let my ask other questions. Can anyone help?

Answer 1

Declare s and set it to be an empty string by default. If q1 is NOT nothing, then assign a value to s. Otherwise s is still an empty string. Later in your code, you can set your text box to be populated with s, and if q1 is empty, s will be too, so nothing will display there.

//declare s and set it to default to an empty string
var s = ''
//make sure q1 is defined and not null
if (q1 != undefined && q1 != null)
   //if q1 is not empty, then set it equal to '_'+n1+'. '+q1, 
   //otherwise s will be an empty string
   if (q1 != '')
       s = '_'+n1+'. '+q1
//if s is empty you can do something, 
//OR you can just set your input value to equal s
if (s == '')
    //do some stuff here