What fires when you change the Price Information?

I noticed that when you change the base price nothing fires?  Is there a way to catch the change of prices in any way during either field change or field validation?

I tried to code something that will update another field with our wholesale price but when I have it fire when the record is submitted the submit button stops working, any ideas?

 function update_wholesale_price(type, name) {   var retail_price = document.getElementById('price_form').priceprice_1_1.value;   if (retail_price != "") {    var wholesale_price = retail_price / 2;    nlapiSetFieldValue('custitem_wholesale_price', wholesale_price);   }      }