This method only works with FileMaker 11:
Change your relationship for the portal to:
Customers::anyField x PortalOccurrence::anyfield (I'm using POrtalOccurrence as I don't know the name you've used here.)
This matches any record in Customers to all records in PortalOccurrence
Now add a portal filter to your portal:
IsEmpty ( Customers::SearchName ) or Customers::SearchName = left ( PortalOccurrence::Name ; length ( customers::SearchName ) )
Use the OnObjectModify trigger on Customers::SearchName to run this script:
Refresh Window [Flush Cached join results]
This script forces the portal to update with each character entered/changed in the searchname field.
Here's a demo file that uses this method (lower left portal) as well as demonstrates a slightly different method for partial text matching in a portal (lower right portal): http://www.4shared.com/file/plr_jbkk/EnhancedValueSelection.html
very good but have any solution without refresh windows my windows appers ...