How to validate user input?

//This code developed by Ramy Mahrous 
//ramyamahrous@hotmail.com
//Its contents is provided "as is", without warranty.

/// <summary>
/// Validates if text matches the pattern
/// </summary>
/// <param name="pattern">Regular experssion pattern</param>
/// <param name="text">Text to be validated</param>
/// <param name="options">Regular experssion options</param>
/// <returns>True if matches, otherwise false</returns>
public bool IsValid(string pattern, string text, RegexOptions options)
{
return System.Text.RegularExpressions.Regex.IsMatch(text, pattern, options);
}

///Some usage

///To validate user input when submitting data
private void SubmitButton_Click(object sender, EventArgs e)
{
if(IsValid(PatternTextBox.Text, textBox2.Text, 
RegexOptions.Multiline | RegexOptions.Compiled))
{
MessageBox.Show("Your input is correct");
}
else
{
MessageBox.Show("Your input is not correct");
}
}

///To validate user input while user type some text
private void textBox2_TextChanged(object sender, EventArgs e)
{
if(IsValid(PatternTextBox.Text, textBox2.Text, 
RegexOptions.Multiline | RegexOptions.Compiled))
{
MessageBox.Show("Your input is correct");
}
else
{
MessageBox.Show("Your input is not correct");
}            
}