function UpdateValues(passedId, prop, newValue) {
var thisData = {};
for ( var i = 0; i < dataContainer.length; i++ ) {
thisData = dataContainer[i];
if (thisData.id == passedId) {
thisData[prop] = newValue;
}
}
}
//Change qty to 99999 for object with index of 1
UpdateValues(1, "qty", 99999);
I've added a fiddle that prints out the result as well: http://jsfiddle.net/4UH9e/