VB.net/ASP.net SELECT problems with SQL

Mhm. This is the VB.net code behind a webpage I'm working with, I've also provided the ASP.net for the frontpage as well. This maybe really simple and I've missed it but everytime I run this code (below) I keep on getting the same error "Invalid column name, Skyrail" where 'Skyrail' is the data in one of the field names (the user alias field). So here's my VB.net code:

'Import the required things Imports System.Data, System.Data.SqlClient Class _Default Inherits System.Web.UI.Page 'Set the variables Dim SQLConnectionString As String Dim SQLConnectionStatus As String = "Closed" Dim SQLConnection As New SqlConnection() Dim SQLCommand As New SqlCommand() Dim SQLData As SqlDataReader 'Function used to open up the SQL connection Function sqlDBConnection() As Object 'Create the Connection String SQLConnectionString = "Data Source=.\SQLEXPRESS;AttachDbFilename=C:\Documents and Settings\Owner\My Documents\Visual Studio 2008\WebSites\Overland\App_Data\Overland.mdf;Integrated Security=True;User Instance=True" 'Set the connection string into the SQL connection SQLConnection.ConnectionString = SQLConnectionString 'Open up the connection SQLConnection.Open() 'Check to see if it was succesful If SQLConnection.State = ConnectionState.Open Then 'If so tell them so ValidationWarning.Text = "Success!" 'Set the connection status to open SQLConnectionStatus = "Open" End If 'Return the connection status Return SQLConnectionStatus End Function 'Function used to close the SQL connection Function sqlDBConnectionClose() As Object 'Close the connection SQLConnection.Close() 'Check to see if it's still open If SQLConnection.State = ConnectionState.Open Then 'If it is tell them that the database closing failed ValidationWarning.Text = "Failed closing database!" 'Keep the connection status as open SQLConnectionStatus = "Open" Else 'Else the connection isn't open so tell them ValidationWarning.Text = "Connection Closed" 'Set the connections status as closed SQLConnectionStatus = "Closed" End If 'Return the connection status Return SQLConnectionStatus End Function 'The sub procedure that validates the boxes Protected Sub ValidateInput_Command(ByVal sender As Object, ByVal e As System.EventArgs) Handles ValidateInput.Command 'Check to see if any of the fields are empty If UserAlias.Text.Length = 0 Or UserName.Text.Length = 0 Or UserPass.Text.Length = 0 Then 'Tell them that they've left a field or two empty ValidationWarning.Text = "You left a field blank!" 'Ensure that the two passwords are equal ElseIf UserPass.Text <> UserPassCheck.Text Then 'If they don't tell them that ValidationWarning.Text = "You're passwords didn't match" 'Check to see if the password length is above 6 ElseIf UserPass.Text.Length < 6 Then 'If not tell them that it's too short ValidationWarning.Text = "You're password is too short!" Else 'We're going to try and open a database connection Try 'Try and open it sqlDBConnection() 'Catch any exceptions Catch exception As System.Exception 'Tell them that it failed and for my use why ValidationWarning.Text = "Could not connect to the database" & exception.Message 'MsgBox(exception.Message, MsgBoxStyle.Critical, "Exception Error") End Try 'If the connection was succesful If SQLConnectionStatus = "Open" Then 'Then we're going to check if the user already exists - doesn't actually work...at all Dim SQLCheckForUser As String = "SELECT * FROM Users WHERE UserAlias = " & UserAlias.Text SQLCommand.Connection = SQLConnection SQLCommand.CommandText = SQLCheckForUser SQLCommand.ExecuteNonQuery() SQLData = SQLCommand.ExecuteReader If SQLData.Read() Then ValidationWarning.Text = "Found the user already?" End If End If End If End Sub 'The sub procedure that closes the connection Protected Sub CloseConnection_Command(ByVal sender As Object, ByVal e As System.EventArgs) Handles CloseConnection.Command 'The function that closes the connection sqlDBConnectionClose() End Sub End Class

And here is my ASP.net page (.aspx, minus the CSS_

<%@ Page Language="VB" AutoEventWireup="false" CodeFile="Default.aspx.vb" Inherits="_Default" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head runat="server"> <title>Overland</title> <style type="text/css"> ... </style> </head> <body> <form runat="server" id="HomePage"> <div class="Surround"> <div class="Navigation"> </div> <div class="Content"> <h1>Overland</h1> <fieldset> <label for="UserAlias">User Alias:</label> <p><asp:TextBox MaxLength="20" ID="UserAlias" runat="server" class="textbox" /></p> <label for="UserName">Real Name:</label> <p><asp:TextBox MaxLength="30" ID="UserName" runat="server" class="textbox" /></p> <label for="UserPass">Password:</label> <p><asp:TextBox MaxLength="50" TextMode="Password" ID="UserPass" runat="server" class="textbox" /></p> <label for="UserPassCheck">Password (again):</label> <p><asp:TextBox MaxLength="50" TextMode="Password" ID="UserPassCheck" runat="server" class="textbox" /></p> <asp:Button Text="Validate" ID="ValidateInput" runat="server"/> <asp:Button Text="Close Connection" ID="CloseConnection" runat="server" /> <p><asp:Label ID="ValidationWarning" runat="server" Text="" /></p> </fieldset> </div> </div> </form> </body> </html>

It's a simple page and currently I'm just messing around/testing. What I'm trying to do is a mockup registration page for a simple user system, it's breaking in the VB.net where I am trying to check whether the user exists already by using a SELECT query: Dim SQLCheckForUser As String = "SELECT * FROM Users WHERE UserAlias = " & UserAlias.Text .

Another problem with this code is that once I've fixed the SELECT query to work how can I check if it actually found anybody?

Thanks for your time.