Need help with InDesign script error (Object undefined)

Hi! I am trying to use a script from a past thread (https://community.adobe.com/t5/indesign-discussions/indesign-script-to-change-the-x-and-y-coordinates-of-page-items/m-p/8583897) and it seemed to work for the posters participating in that thread. This script is supposed to take text frames at a certain x, y coordinate and move them using to new x, y coordinates. However, I keep receiving an error that says Error string: undefined is not an object whenever I enter the coordinates.

I'm using Adobe Indesign 2024 (v19.0 latest version). I am by no means acquainted with JavaScript at all so I have no idea where it is going wrong. Thank you!

This is the script: 

var myDoc = app.activeDocument;
var w = new Window ('dialog {alignChildren: "top"}', 'Move TF (x,y) To (newx, newy)!');
 w.alignChildren = "right";
    var group1 = w.add ('group');
        group1.add ('statictext {text: "Type the old x:"}');
    var UIx = group1.add ("edittext", undefined, 0);
        UIx.characters = 5;
        UIx.minimumSize.width = 60;
        UIx.maximumSize.width = 60;
        UIx.active = true;
    var group2 = w.add ('group');
        group2.add ('statictext {text: "… and the old y:"}');
    var UIy = group2.add ("edittext", undefined, 0);
        UIy.characters = 5;
        UIy.minimumSize.width = 60;
        UIy.maximumSize.width = 60;
    var group3 = w.add ('group');
        group3.add ('statictext {text: "Type the new x:"}');
    var UInewx = group3.add ("edittext", undefined, 0);
        UInewx.characters = 5;
        UInewx.minimumSize.width = 60;
        UInewx.maximumSize.width = 60;
    var group4 = w.add ('group');
        group4.add ('statictext {text: "… and the new y:"}');
    var UInewy = group4.add ("edittext", undefined, 0);
        UInewy.characters = 5;
        UInewy.minimumSize.width = 60;
        UInewy.maximumSize.width = 60;
    var buttons = w.add ('group {alignment: "center"}');
        buttons.add ('button {text: "OK"}');
        buttons.add ('button {text: "Cancel"}');            
if (w.show () == 1) {
    var x = Number (UIx.text);
    x = x.toFixed(2);
    var y = Number (UIy.text);
    y = y.toFixed(2);
    var newx = UInewx.text; 
    var newy = UInewy.text;
    }
else
exit ();
app.doScript("main()", ScriptLanguage.javascript, undefined, UndoModes.FAST_ENTIRE_SCRIPT, "Move TF (x,y) To (newx, newy)!");

function main()
{  
var myTF = myDoc.textFrames.everyItem().getElements();
for ( i = 0; i < myTF.length; i++)  
     {    
        var gB = myTF.geometricBounds;    
        var y1 = gB[0].toFixed(2);  
        var x1 = gB[1].toFixed(2);
        if ( y1 == y && x1 == x )  myTF.move([newx, newy]);
     }
}