You can use the ctrl.getPeer(field) function to return the other field control in the inline mode.
Syntax
ctrl.getPeer(field);
Arguments
field
the name of the other field in the same row when in an inline mode.
Return value
Returns the other field control from the same page in the same row when in an inline mode. Works similar to the Runner.getControl function, but should be used in Field events.
Example
Get the 'price' control in an inline mode and then set its value to 1000.
var ctlPrice = ctrl.getPeer('price');
ctlPrice.setValue( 1000 );
See also:
•JavaScript API: Control object > getControl()
•JavaScript API: Control object > setValue()