how to get the message of SqlException error?

With this code below, i get the number of the SqlException error. But i want to see the full message instead of the error number. For instance, instead of getting error number 207, i would like to get its equivalent message: "invalid column name". Is that possible?
try
{
..
}
catch (SqlException ex)
{
int a = ex.Number;
ClientScript.RegisterStartupScript(this.GetType(), "", "alert('Errornumber:' + '" + a + "');", true);
}
Thanks

You can display in response.writeline as shown:

try
{
..
}
catch (SqlException ex)
{
response.write(ex.Message.ToString());
}

Instead of storing ex.Number in int, store ex.Message in string to get error message.

ex.Number identifies type of Error.

To get detailed error message:

try{
}
catch(SqlException ex)
{
string a = ex.Message.ToString();
ClientScript.RegisterStartupScript(this.GetType(), "", "alert('Errornumber:' + '" + a + "');", true);
}

catch (SqlException ex)
{
string a = ex.Message.ToString();
ClientScript.RegisterStartupScript(this.GetType(), "", "alert('Message:' + '" + a + "');", true);
}

Thanks, but this is for a Console App. My application is WSP. It doesn't work.

Please see below example,

public static void ShowSqlException(string connectionString)
{
string queryString = "EXECUTE NonExistantStoredProcedure";
StringBuilder errorMessages = new StringBuilder();
using (SqlConnection connection = new SqlConnection(connectionString))
{
SqlCommand command = new SqlCommand(queryString, connection);
try
{
command.Connection.Open();
command.ExecuteNonQuery();
}
catch (SqlException ex)
{
for (int i = 0; i < ex.Errors.Count; i++)
{
errorMessages.Append("Index #" + i + "\n" +
"Message: " + ex.Errors[i].Message + "\n" +
"LineNumber: " + ex.Errors[i].LineNumber + "\n" +
"Source: " + ex.Errors[i].Source + "\n" +
"Procedure: " + ex.Errors[i].Procedure + "\n");
}
Console.WriteLine(errorMessages.ToString());
}
}
}