How to hide button in CRM given a condition on the field of the records to be displayed?

Hi, I'm using Javascript to hide a button in the Sub-opportunity panel of opportunity object in Oracle CRM On Demand. I can hide the button already but there's an additional requirement. There's a field named Opportunity Type (Picklist) in the Opportunity object. The button will be hide when the value of Opportunity Type is EMEA Product, Network Power. Is this possible? I tried to create a code but it is not working. I'm thinking that the reason might be since the Opportunity Type field will be loaded simultaneously as the button is loaded that's why condition was not satisfied. Can