How to assign a method's output to a textbox value without code behind

<%@ Page Language="VB" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
    Public TextFromString As String = "test text test text"
    Public TextFromMethod As String = RepeatChar("S", 50) 'SubSonic.Sugar.Web.GenerateLoremIpsum(400, "w")

    Public Function RepeatChar(ByVal Input As String, ByVal Count As Integer)
        Return New String(Input, Count)
    End Function
</script>
<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
    <title>Test Page</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <%=TextFromString%>
        <br />
        <asp:TextBox ID="TextBox1" runat="server" Text="<%# TextFromString %>"></asp:TextBox>
        <br />
        <%=TextFromMethod%>
        <br />
        <asp:TextBox ID="TextBox2" runat="server" Text="<%# TextFromMethod %>"></asp:TextBox>
    </div>
    </form>
</body>
</html>

<asp:Label runat="server" ID="label1"><%=TextFromString%></asp:Label>

<asp:TextBox ID="TextBox3" runat="server">Hello</asp:TextBox>

<asp:TextBox ID="TextBox4" runat="server"><%=TextFromString%></asp:TextBox>

<%= TextFromMethod %>

<%# TextFromMethod %>

<%$ ConnectionStrings:Database %>

Private Function Page_Load(sender as Object, e as EventArgs)
   If Not IsPostback Then
      Me.DataBind()
   End If
End Function

<input type="text" id="TextBox4" runat="server" value="<%=TextFromString%>" />