def pc_search(self):
#Get the postcode to search for
qid = QInputDialog()
title = "Enter Postcode"
label = "Postcode:"
mode = QLineEdit.Normal
default = ""

pc, ok = QInputDialog.getText(qid, title, label, mode, default)
print pc

# Open the address data table and search for the postcode
uri = QgsDataSourceURI()
uri.setConnection("ictdsgdev5", "5432", "gistest", "postgres", "gistest1")
uri.setDataSource("public", "OSADDBASE_LEICS", "geom", "POSTCODE like '" + pc.upper() + "%" + "'")
print uri.sql()
vlayer = QgsVectorLayer(uri.uri(), "Address", "postgres")
print vlayer.isValid()

if vlayer.isValid():
    # Add the address layer to the list of layers
    QgsMapLayerRegistry.instance().addMapLayer(vlayer)

    # Select the found addresses and zoom to them
    selectList=[]

    for feature in vlayer.getFeatures():
        geom = feature.geometry()
        selectList.append(feature.id())

    vlayer.setSelectedFeatures(selectList)

else:
    #MessageBox displaying no address found
    QMessageBox.information(None, "Information", "No address(es) found for " + pc.upper())