My intial problem was to solve a simultaneous equation using excel.

You can do this using Tools > Solver...

Now I wanted to create a macro so everytime I change my constraints< I can run the macro which would in turn run the commands in Solver...

I did this BUT when I actually ran the macro again I got this error:

Compile Error:
Sub or Function not defined.

Macro:
Sub last()
'
' last Macro
' Macro recorded 19.04.2006 by Lewis Holland
'

'
SolverOk MaxMinVal:=1, ValueOf:="0", ByChange:="$D$9:$D$10"
SolverAdd CellRef:="$A$9:$A$10", Relation:=2, FormulaText:="$B$9:$B$10"
SolverOk MaxMinVal:=1, ValueOf:="0", ByChange:="$D$9:$D$10"
SolverSolve
End Sub

Can anyone help solve this?
Can you record a macro which actually uses this Solver.. function?