Reset button clearing all data

[EBahn]

I had an IF formula where I wanted to add a text if aa value was "0", all worked great but when I ran the VBA to reset or clear data- It's a calc sheet- the If function formula disappears too.
What can I do to remove that? The cells that i want the IF are in M15-23. Any thoughts or ideas?

Sub ClearData()


Worksheets("DESIGN").Range("C15").Value = "NONE"
Worksheets("DESIGN").Range("C17").Value = "No Pic"
Worksheets("DESIGN").Range("C18").Value = "No Sic"
Worksheets("DESIGN").Range("K7").Value = ""
Worksheets("DESIGN").Range("d6").Value = ""
Worksheets("DESIGN").Range("d6").Value = ""
Worksheets("DESIGN").Range("G16").Value = "'"
Worksheets("DESIGN").Range("m15:m23").Value = "'"
Worksheets("DESIGN").Range("n15:n23").Value = "'"
Worksheets("DESIGN").Range("g18").Value = ""
Worksheets("DESIGN").Range("k6").Value = ""
Worksheets("DESIGN").Range("p2427").Value = ""
Worksheets("DESIGN").Range("d28").Value = ""
Worksheets("DESIGN").Range("O15:O23").Value = ""
Worksheets("DESIGN").Range("P15:P23").Value = ""
Worksheets("DESIGN").Range("N71:N72").Value = ""
Worksheets("DESIGN").Range("N74:N75").Value = ""

 

[Fluff]

Hi & welcome to MrExcel.
Just remove this line

Worksheets("DESIGN").Range("m15:m23").Value = "'"