How to export the images and save them as a chart title name

Could someone please help me in the code which would export the images and save them as a chart title name IT is exporting as a GIF but not PNG

I would be grateful if someone would please modify my code :

Sub export()

Dim ws As Excel.Worksheet
Dim SaveToDirectory As String
Dim objChrt As ChartObject
Dim myChart As Chart

SaveToDirectory = ActiveWorkbook.Path & "\"

For Each ws In ActiveWorkbook.Worksheets

ws.Activate

worksheetName = ws.Name
If worksheetName = "EUROPE + ENG" Or worksheetName = "EUROPE" Or worksheetName = "NEW NORTH" Then

For Each objChrt In ws.ChartObjects

objChrt.Activate
Set myChart = objChrt.Chart


myFileName = SaveToDirectory & ws.Name & "_" & objChrt.Name & ".png"


On Error Resume Next
Kill SaveToDirectory & ws.Name & Name & ".png"
On Error GoTo 0
ActiveWindow.Zoom = 275
myChart.export Filename:=myFileName, FilterName:="PNG"
ActiveWindow.Zoom = 100

Next

End If

Next

MsgBox "Success !! All charts have been exported"
End Sub