RegisterClientScriptBlock, RegisterStartupScript

Button1.Attributes.Add ( "onclick", "___JavaScript____");
	||  
Button1.Attributes[ "onclick"] =  "___JavaScript______ ;

   protected void Page_Load(object sender, EventArgs e)
    {
        Image2.Attributes.Add("onclick", "javascript:myFunc();");
        ImageButton2.Attributes.Add("onclick", "javascript:myFunc();return false;");
    }
    protected void ImageButton1_Click(object sender, ImageClickEventArgs e)
    {
        Label1.Text = TextBox1.Text;
    }
    protected void ImageButton2_Click(object sender, ImageClickEventArgs e)
    {
        Label1.Text = "#################";
    }
    protected void ImageButton3_Click(object sender, ImageClickEventArgs e)
    {
        Label1.Text = "#################";
 		if(! ClientScript.IsClientScriptBlockRegistered("myClick"))
            ClientScript.RegisterStartupScript(typeof(Page), "myClick", 
			"");
    }




					js_RadioButton_CheckBox     Default.aspx

private void Page_Load(object sender, System.EventArgs e)
{
       if (!IsPostBack)
        {
            RadioButton1.Attributes.Add("onclick", string.Format("javascript:func1('{0}','{1}','{2}','{3}');", RadioButton1.ClientID, RadioButton2.ClientID, Button1.ID, Button2.ID));
            RadioButton2.Attributes.Add("onclick", string.Format("javascript:func1('{0}','{1}','{2}','{3}');", RadioButton2.ClientID, RadioButton1.ClientID, Button2.ID, Button1.ID));
            CheckBox1.Attributes.Add("onclick", string.Format("javascript:func2('{0}','{1}');", CheckBox1.ClientID, Button3.ID));
            CheckBox2.Attributes.Add("onclick", string.Format("javascript:func2('{0}','{1}');", CheckBox2.ClientID, Button4.ID));
        }
}







					js_Simple_Events		Default.aspx.cs

private void Page_Load(object sender, System.EventArgs e)
{
        //TextBox1.Attributes["onClick"] = "javascript : alert('Click on TextBox')";
        TextBox1.Attributes["onDblClick"] = "javascript : alert('Double Click on TextBox')";

        //TextBox1.Attributes["onChange"] = "javascript : alert('TextBox is changed')";
        //TextBox1.Attributes["onSelect"] = "javascript : alert('TextBox is Selected')";

        //TextBox1.Attributes["onFocus"] = "javascript : alert('TextBox in focus')";
        //TextBox1.Attributes["onBlur"] = "javascript:alert('Focus lost from TextBox')"

        //TextBox1.Attributes["onKeyDown"] = "javascript : alert('TextBox KeyDown')";
        //TextBox1.Attributes["onKeyUp"] = "javascript : alert('TextBox KeyUp')";
        //TextBox1.Attributes["onKeyPress") = "javascript : alert('TextBox KeyPress')";

        //TextBox1.Attributes["onMouseOut"] = "javascript : alert('TextBox MouseOut')";
        //TextBox1.Attributes["onMouseMove"] = "javascript : alert('TextBox MouseMove')";
        //TextBox1.Attributes["onMouseDown"] = "javascript : alert('TextBox MouseDown')";
        //TextBox1.Attributes["onMouseUp"] = "javascript : alert('TextBox MouseUp')";
        //TextBox1.Attributes["onMouseOver"] = "javascript : alert('TextBox MouseOver')";
}