Visualforce controller with a JavaScript remoting method to retrieve a matching record after scanning a barcode.

BarcodeSF1Ctrl

public with sharing class BarcodeSF1Ctrl 
{
	@RemoteAction
	public static String getRecordFromBarcode(String bcStr)
	{
		String result;
		List<String> eles=bcStr.split(':');
		
		String code=eles[1].trim();
		List<Account> accs=[select id, Barcode__c from Account where Barcode__c=:code];
		if (0!=accs.size())
		{
			result=accs[0].id;
		}
		else
		{
			result='Error: no record matching ' + code + ' found';
		}
		
		return result;
	}
}