fix: add clear button to "Practice.ValidWeb"

Practice/ValidWeb/Forma1-clear.aspx.cs

@@ -0,0 +1,22 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Web;
+using System.Web.UI;
+using System.Web.UI.WebControls;
+
+namespace ValidWeb
+{
+    public partial class Forma1 : System.Web.UI.Page
+    {
+
+        protected void Button2_Click(object sender, EventArgs e)
+        {
+            Session.Clear();
+            for (int i = Table1.Rows.Count-1; i > 0; i--)
+            {
+                Table1.Rows.RemoveAt(i);
+            }
+        }
+    }
+}

Practice/ValidWeb/Forma1.aspx

@@ -41,6 +41,9 @@
                 <br />
                 <asp:Button ID="Button1" runat="server" Text="Registruotis" OnClick="Button1_Click" />
                 <br />
+                <br />
+                <asp:Button ID="Button2" runat="server" Text="Išvalyti" OnClick="Button2_Click" />
+                <br />
       <br />
                 <asp:Table ID="Table1" runat="server" BackColor="#FFFFCC" BorderColor="Black" BorderStyle="Solid" BorderWidth="1px" GridLines="Both">
                 </asp:Table>

Practice/ValidWeb/Forma1.aspx.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using System.Text.RegularExpressions;
 using System.Web;
 using System.Web.UI;
 using System.Web.UI.WebControls;
@@ -45,10 +46,15 @@ namespace ValidWeb
         protected void Button1_Click(object sender, EventArgs e)
         {
             string name = TextBox1.Text;
+            if (Regex.IsMatch(name, @"[^a-zA-Z]")) { return; }
+
             string surname = TextBox2.Text;
+            if (Regex.IsMatch(surname, @"[^a-zA-Z]")) { return; }
+
             string school = TextBox3.Text;
             string age = DropDownList1.Text;
-            string language = CheckBoxList1.sele;
+            string language = CheckBoxList1.SelectedValue;
+            
             string user = String.Join("|", name, surname, school, age, language);
             if (Session["users"] == null) {
                 Session["users"] = user;
@@ -70,5 +76,7 @@ namespace ValidWeb
 
             Table1.Rows.Add(row);
         }
+
+        
     }
 }

Practice/ValidWeb/Forma1.aspx.designer.cs

@@ -185,6 +185,15 @@ namespace ValidWeb
         /// </remarks>
         protected global::System.Web.UI.WebControls.Button Button1;
 
+        /// <summary>
+        /// Button2 control.
+        /// </summary>
+        /// <remarks>
+        /// Auto-generated field.
+        /// To modify move field declaration from designer file to code-behind file.
+        /// </remarks>
+        protected global::System.Web.UI.WebControls.Button Button2;
+
         /// <summary>
         /// Table1 control.
         /// </summary>