The following procedure works in the command class to change dimstyle variables.
I can used the command DimStyleChange to change dim style variables.

[CommandMethod("DimStyleChange")]
// public static void CreateModifyDimStyle1(string DimStyleName, out string message)
public void StandardStyleChange()
{
String DimStyleName;
DimStyleName = "Standard";
System.Windows.Forms.MessageBox.Show("Test");
// Initialise the message value that gets returned by an exception (or not!)
message = string.Empty;

try
{
using (Transaction tr = Application.DocumentManager.MdiActiveDocument.Tran sactionManager.StartTransaction())
{
Database db = Application.DocumentManager.MdiActiveDocument.Data base;
DimStyleTable dst = (DimStyleTable)tr.GetObject(db.DimStyleTableId, OpenMode.ForWrite, true);
//System.Windows.Forms.MessageBox.Show("Test");
// Initialise a DimStyleTableRecord
DimStyleTableRecord dstr = null;
// If the required dimension style exists
if (dst.Has(DimStyleName))
{
// get the dimension style table record open for writing
dstr = (DimStyleTableRecord)tr.GetObject(dst[DimStyleName], OpenMode.ForWrite);
}
else
// Initialise as a new dimension style table record
dstr = new DimStyleTableRecord();

// Set all the available dimension style properties
// Most/all of these match the variables in AutoCAD.
dstr.Name = DimStyleName;



// If the dimension style doesn't exist
if (!dst.Has(DimStyleName))
{
// Add it to the dimension style table and collect its Id
Object dsId = dst.Add(dstr);
// Add the new dimension style table record to the document
tr.AddNewlyCreatedDBObject(dstr, true);
}
dstr.Dimasz = 0.1875;//Arrow head size
dstr.Dimscale = 5;//Dim Scale
dstr.Dimtxt = 0.085;//Dim Text size

// Commit the changes.
tr.Commit();
}
}
catch (Autodesk.AutoCAD.Runtime.Exception e)
{
message = e.Message.ToString();
}
}
But when I create a form button and try to start the above method the proceedure
does not make changes. So what should I look at to trouble shoot?

Here is my button code.
private void button7_Click(object sender, EventArgs e)
{
MyCommands ObjMycommands = new MyCommands();
ObjMycommands.StandardStyleChange();

}
Thank you,