I have a task where participants are asked to move two chairs and the computer records the location of the chairs. I want to be sure that participants move the chairs before being able to click on the next button.



One way I was thinking to do this is to disable the next button until the condition of moving the chair is met. The computer records the movement of the chairs with pixels using embedded data. If participants do not move the chairs the values for the embedded data fields "you x" and "you y" are left blank. Is there a way to write java code so that the next button will appear only if the chair is moved (if embedded data field is not blank)? I am not a programmer so am not sure what to do.



Here is a link to my task: https://qaz1.az1.qualtrics.com/jfe/form/SV_9Griq4aYcfbUBWl



Here is the embedded data code:

![](https://uploads-us-west-2.insided.com/qualtrics-us/attachment/ao_ap33yscn6m6g.jpg ""



Here is the code for the java script I currently have for this question:



Qualtrics.SurveyEngine.addOnload(function()

{

/*Place your JavaScript here to run when the page loads*/



});



Qualtrics.SurveyEngine.addOnReady(function() {



//variables

var draggableClassName = ".chair"; // the class name of elements that should be draggable

var edField = "distance"; // this will be the name of the Embedded Data field with the distance.

var partnerx = "aPosition"; //this will get center x coordinate of Partner Chair

var partnery = "aPosition"; //this will get center y coordinate of Partner Chair

var youx = "bPosition"; //this will get center x coordinate of You Chair

var youy = "bPosition"; //this will get center y coordinate of You Chair



jQuery( function() {

jQuery( draggableClassName ).draggable({

stop: function() {

var distance = getDistanceBetweenElements(document.getElementById("Chair1"),

document.getElementById("Chair2"));

Qualtrics.SurveyEngine.setEmbeddedData('edField', distance);

}

});

});



var getPositionAtCenter = function (element) {

var data = element.getBoundingClientRect();

return {

x: data.left + data.width / 2,

y: data.top + data.height / 2

};

};



var getDistanceBetweenElements = function(a, b) {

var aPosition = getPositionAtCenter(a);

Qualtrics.SurveyEngine.setEmbeddedData('partnerx', aPosition.x);

Qualtrics.SurveyEngine.setEmbeddedData('partnery', aPosition.y);

var bPosition = getPositionAtCenter(b);

Qualtrics.SurveyEngine.setEmbeddedData('youx', bPosition.x);

Qualtrics.SurveyEngine.setEmbeddedData('youy', bPosition.y);



return Math.sqrt(

Math.pow(aPosition.x - bPosition.x, 2) +

Math.pow(aPosition.y - bPosition.y, 2)

);

};



});



Qualtrics.SurveyEngine.addOnUnload(function()

{

/*Place your JavaScript here to run when the page is unloaded*/



});