Custom function slowing workbook speed

[PIPPIBOOKS]

I have at work an excel file I use for billing purposes. It contains at least 100 seperate sheets, each named by the job number (we are a pump service company). I have posted things before about this problem and I hope this will not get me in trouble but I am still having the same problem...I am trying again and this time giving as much information as I can so hopefully this time is easier to fully understand my issue. I am enclosing an attatchment. This is an example of just one job out of 100 in the same workbook. On top of things I am new at forums and limited in my excel programming abilities. Please don't kick me off the forum for not asking my question right the first time.

Anyway I have code written as of now into a Module 2 as follows:

Function ColorAndName(ColRng As Range, NameRng As Range, Nme As String, coloffset As Integer)
  Application.Volatile
  lcolor = ColRng.Interior.ColorIndex
  total = 0
  For Each ce In NameRng
    If ce.Interior.ColorIndex = lcolor And ce.Value = Nme Then
      total = total + ce.Offset(0, coloffset)
    End If
  Next ce
  ColorAndName = total
End Function

Module 1 contains a macro I have written (with help) to hide rows I don't need to see once I am ready to print:

Sub HideRows()
    Application.ScreenUpdating = False
    With Range("P1:P307")
        .Rows.Hidden = False
        .SpecialCells(xlCellTypeFormulas, xlLogical).Rows.Hidden = True
          End With
End Sub

My problems are:
1) I work in this workbook every day doing data entry...when I am just entering data I do not need it to calculate every time I enter a number as it does now. It extremely slows down entering data so I end up going into Module 2 and temporarily deleting its code so I can enter data faster.

2) I really don't need Module 2 to work for me until the job is done and I have entered all the guys time for all the days they worked on that job. I thought maybe I could convert it into a macro so I could tell it to run when I was ready - but I am a novice at this so that probably isn't the answer.

If someone could take the time to help me it would be SO APPRECIATED!!!