member not found error is seen.

any suggestions why I am getting this error:

Run the below script:

var flag = 0;
for(var i= 0;i<Grid.wRowCount;i++){
if(String(Grid.wValue(i,1))== "500322" && String(Grid.wValue(i,2))== "COUNTRY" && String(Grid.wValue(i,3))== "TEST" && String(Grid.wValue(i,4))== "Canada"){
Log.Message("Row exists");
flag = 1;
break;