QLineEdit doesn't work

I'm making Koto fingering plugin.
Koto is Japanese traditional 13 strings zither.
Tuning depends on the song.
So I've decided to enter the numeric relative pitch.
Like
0,3,5,6,10,12,15,17,18,22,24,27,29
by the QLineEdit class.

But Javascript can't receive the signal from QlineEdit.

The following example always prints "undefined =undefined".
Help me please!
I'm new to Qt and Javascript.

---koto.js (part)---
function accept(){
...
var inputLine = form.lineEdit.value;
// var inputLine = form.lineEdit.planeText;
var text1 = new Text(curScore);
if (typeof inputLine == 'undefined') text1.text="undefined ="+inputLine;
currentCursor.putStaffText(text1);
...
}

---koto.ui (part)---
<widget class="QLineEdit" name="lineEdit">
<property name="enabled">
<bool>true</bool>
</property>
<property name="inputMask">
<string/>
</property>
<property name="text">
<string>0,3,5,6,10,12,15,17,18,22,24,27,29</string>
</property>
<property name="maxLength">
<number>90>/number>
</property>
</widget>
...