Hoew to made a singleton Idea with multi forms

Question

Hi my friends , I have MDI windows application each of child_form have grid also I has class contain a timer that sent message to the container application like the following code So my question how can i change all child_forms at Same time Exactly when that class sent message . Code : public class Class1 { System.Windows.Forms.Timer ti = new System.Windows.Forms.Timer(); public Class1() { ti.Tick += new EventHandler(ti_Tick); } void ti_Tick(object sender, EventArgs e) { //Should be modify All MDI child forms } }