diff --git a/applications/lazstats/source/forms/analysis/matrix_manipulation/matmanunit.pas b/applications/lazstats/source/forms/analysis/matrix_manipulation/matmanunit.pas
index 1365d9f06..213d15103 100644
--- a/applications/lazstats/source/forms/analysis/matrix_manipulation/matmanunit.pas
+++ b/applications/lazstats/source/forms/analysis/matrix_manipulation/matmanunit.pas
@@ -288,31 +288,40 @@ implementation
 uses
   MainUnit;
 
-{ TMatManFrm }
+const
+  FILE_FILTERS =
+    'Matrix (*.mat)|*.mat;*.MAT|' +
+    'Column Vector (*.cve)|*.cve;*.CVE|'+
+    'Row Vector (*.rve)|*.rve;*.RVE|'+
+    'Scalar (*.scl)|*.sca;*.SCA|'+
+    'All (*.*)|*.*';
 
 
+{ TMatManFrm }
+
 procedure TMatManFrm.FormCreate(Sender: TObject);
 begin
-  if ScriptEditorFrm <> nil then
+  if ScriptEditorFrm = nil then
     Application.CreateForm(TScriptEditorFrm, ScriptEditorFrm);
-  if ScriptOptsFrm <> nil then
+  if ScriptOptsFrm = nil then
     Application.CreateForm(TScriptOptsFrm, ScriptOptsFrm);
-  if OutputFrm <> nil then
+  if OutputFrm = nil then
     Application.CreateForm(TOutputFrm, OutputFrm);
 end;
 
 procedure TMatManFrm.FormShow(Sender: TObject);
+const
+  matExt = '.mat';
+  cvecExt = '.cve';
+  rvecExt = '.rve';
+  scaExt = '.sca';
 var
   count, index : integer;
-  filename, matext, cvecext, rvecext, scaext, extstr : string;
+  filename, extstr : string;
   scriptopts : TextFile;
   checked : integer;
 begin
   ResetGrids(Self);
-  matext := '.MAT';
-  cvecext := '.CVE';
-  rvecext := '.RVE';
-  scaext := '.SCA';
   scripteditorfrm.FileListBox1.Directory := Options.DefaultDataPath;
   scripteditorfrm.FileListBox1.Update;
   count := scripteditorfrm.FileListBox1.Items.Count;
@@ -326,9 +335,9 @@ begin
     if extstr = rvecext then RowVecsBox.Items.Add(filename);
     if extstr = scaext then ScalarsBox.Items.Add(filename);
   end;
-  if FileExists('Options.SCR') then
+  if FileExists('options.scr') then
   begin
-    AssignFile(scriptopts, 'Options.SCR');
+    AssignFile(scriptopts, 'options.scr');
     Reset(scriptopts);
     Readln(scriptopts,checked);
     if checked = 1 then scriptoptsfrm.CheckGroup1.Checked[0] := true;
@@ -340,19 +349,18 @@ end;
 
 procedure TMatManFrm.Grid1Click(Sender: TObject);
 begin
-     CurrentGrid := 1;
-     CurrentObjName := MatOneEdit.Text;
-     GridNoEdit.Text := IntToStr(1);
-     if ((Rows1 > 2) and (Cols1 > 2)) then CurrentObjType := 1;
-     if ((Rows1 > 2) and (Cols1 = 2)) then CurrentObjType := 2;
-     if ((Rows1 = 2) and (Cols1 > 2)) then CurrentObjType := 3;
-     if ((Rows1 = 2) and (Cols1 = 2)) then CurrentObjType := 4;
+  CurrentGrid := 1;
+  CurrentObjName := MatOneEdit.Text;
+  GridNoEdit.Text := IntToStr(1);
+  if ((Rows1 > 2) and (Cols1 > 2)) then CurrentObjType := 1;
+  if ((Rows1 > 2) and (Cols1 = 2)) then CurrentObjType := 2;
+  if ((Rows1 = 2) and (Cols1 > 2)) then CurrentObjType := 3;
+  if ((Rows1 = 2) and (Cols1 = 2)) then CurrentObjType := 4;
 end;
 
 procedure TMatManFrm.Grid1KeyPress(Sender: TObject; var Key: char);
 var
    instr : string;
-
 begin
      if Ord(Key) = 13 then  // return pressed
      begin
@@ -1507,14 +1515,14 @@ end;
 
 procedure TMatManFrm.OpenFileMnuClick(Sender: TObject);
 begin
-     OpenDialog1.Filter := 'Matrix (*.mat)|*.MAT|Col.Vector (*.CVE)|*.CVE|RowVector (*.RVE)|*.RVE|Scaler (*.scl)|*.SCA|All (*.*)|*.*';
+     OpenDialog1.Filter := FILE_FILTERS;
      OpenDialog1.FilterIndex := CurrentObjType;
      case CurrentObjType of
-          1 : OpenDialog1.DefaultExt := '.MAT';
-          2 : OpenDialog1.DefaultExt := '.CVE';
-          3 : OpenDialog1.DefaultExt := '.RVE';
-          4 : OpenDialog1.DefaultExt := '.SCA';
-          else OpenDialog1.DefaultExt := '.MAT';
+          1 : OpenDialog1.DefaultExt := '.mat';
+          2 : OpenDialog1.DefaultExt := '.cve';
+          3 : OpenDialog1.DefaultExt := '.rve';
+          4 : OpenDialog1.DefaultExt := '.sca';
+          else OpenDialog1.DefaultExt := '.mat';
      end;
      GridNoEdit.Text := IntToStr(CurrentGrid);
      GetGridData(CurrentGrid);
@@ -3914,13 +3922,13 @@ var
    BackUpName : string;
 
 begin
-     SaveDialog1.Filter := 'Matrix (*.mat)|*.MAT|Col.Vector (*.CVE)|*.CVE|RowVector (*.RVE)|*.RVE|Scaler (*.scl)|*.SCA|All (*.*)|*.*';
+     SaveDialog1.Filter := FILE_FILTERS;
      SaveDialog1.FilterIndex := CurrentObjType;
      case CurrentObjType of
-          1 : SaveDialog1.DefaultExt := '.MAT';
-          2 : SaveDialog1.DefaultExt := '.CVE';
-          3 : SaveDialog1.DefaultExt := '.RVE';
-          4 : SaveDialog1.DefaultExt := '.SCA';
+          1 : SaveDialog1.DefaultExt := '.mat';
+          2 : SaveDialog1.DefaultExt := '.cve';
+          3 : SaveDialog1.DefaultExt := '.rve';
+          4 : SaveDialog1.DefaultExt := '.sca';
      end;
      BackUpName := ExtractFileName(CurrentObjName);
      SaveDialog1.FileName := BackUpName;
@@ -6586,7 +6594,7 @@ begin
 end;
 
 procedure TMatManFrm.DynMatPrint(var xmat: DynMat; rows, cols: integer;
-  var title: string; var ColHeadings: Dynstrarray);
+  var title: string; var ColHeadings: DynStrArray);
 var
    i, j, first, last, nflds : integer;
    done : boolean;