Anyone know what this error message means?

Hi everyone,

My team has put together some JS to create an additional constant sum total on a matrix table. It works perfectly, but when we go to submit the data on the preview it comes up with the below error:

!

The code we're using is below - it also includes functions to replace zeros with blank space and widens the input boxes:

Qualtrics.SurveyEngine.addOnload(function()
{
/*Place your JavaScript here to run when the page loads*/
var a = 0;
var b = 0;


while (a<6){
while (b<9){
if(this.getChoiceValue(a,b) == 0) {
this.setChoiceValue(a,b,"");
}
b++;
}
b = 0;
a++;
}


{
var inputWidth = "75px";
var q = jQuery("#"+this.questionId);
q.find('Input').css("width", inputWidth);
q.find('.SumInput').css("width", inputWidth);
q.find('.SumTotal').css("width", inputWidth);
q.find('.InputText').css("width", inputWidth);
};

});


Qualtrics.SurveyEngine.addOnReady(function()
{
/*Place your JavaScript here to run when the page is fully displayed*/

this.questionclick = function(event,element){

var i =0; /*Setting column number for loopage*/

while (i<9){
var a = parseInt(this.getChoiceValue(1,i),10);
var b = parseInt(this.getChoiceValue(2,i),10);
var c = parseInt(this.getChoiceValue(3,i),10);
var d = parseInt(this.getChoiceValue(4,i),10);
var e = parseInt(this.getChoiceValue(5,i),10);


if(isNaN(a)){ /*check if div by 0*/
a= 0;
}
if(isNaN(b)){ /*check if div by 0*/
b= 0;
}
if(isNaN(c)){ /*check if div by 0*/
c= 0;
}
if(isNaN(d)){ /*check if div by 0*/
d= 0;
}
if(isNaN(e)){ /*check if div by 0*/
e= 0;
}
var x = a+b+c+d+e ;

this.setChoiceValue (6,i,x);


/*Increase column number*/
i++;

}}
});


Qualtrics.SurveyEngine.addOnUnload(function()
{
/*Place your JavaScript here to run when the page is unloaded*/

});


Any ideas on the error??

Thanks,

Rose