Replace when cell isblank

[sitzalke]

Hi. I want to ask one problem,
I have one column which is column "M".
If there are any blank cell in column "M", then it will replace with "MPTV".
So, it will loop start from row 2 until lastrow.
here is coding vba that I've try but cannot.

Sub REPLACEBLANK()
    'replace Blank to MPTV
    'in column M (SLoc column)
    Lastrow1 = Range("M" & Rows.Count).End(xlUp).Row
      Columns("M", Rows.Count).End(xlUp).Replace what:=Null, _
                            replacement:="MPTV", _
                            lookat:=xlPart, _
                            SearchOrder:=xlByRows, _
                            MatchCase:=False, _
                            SearchFormat:=False, _
                            ReplaceFormat:=False
End Sub

Please help me. thanks all

 

[footoo]

Sub REPLACEBLANK()
'replace Blank to MPTV
'in column M (SLoc column)
On Error Resume Next
Range("M1:M" & Cells(Rows.Count, "M").End(xlUp).Row) _
    .SpecialCells(xlCellTypeBlanks) = "MPTV"
End Sub

 

[sitzalke]

Sub REPLACEBLANK()
'replace Blank to MPTV
'in column M (SLoc column)
On Error Resume Next
Range("M1:M" & Cells(Rows.Count, "M").End(xlUp).Row) _
    .SpecialCells(xlCellTypeBlanks) = "MPTV"
End Sub

Thanks it works. Thanks a lot.

 

[sitzalke]

Sub REPLACEBLANK()
'replace Blank to MPTV
'in column M (SLoc column)
On Error Resume Next
Range("M1:M" & Cells(Rows.Count, "M").End(xlUp).Row) _
    .SpecialCells(xlCellTypeBlanks) = "MPTV"
End Sub

I am sorry, I try to run with all the data, but its not work.
It only works if the all data are empty. If there are few data in column "M",
such as,

Column M |
123
123
123
113

213

313
133
-------------

It doesn't fill the blank with "MPTV". T_T

 

[footoo]

Are the cells really blank?
Check with : =ISBLANK(M1) If blank it will return TRUE

 

[sitzalke]

Are the cells really blank?
Check with : =ISBLANK(M1) If blank it will return TRUE

okay, now I know. There are spaces inside the cells. So what I need to do is trim it right? okay noted, thanks a lot.