Question

I want to validate two TextBoxes in my WebPage and I want to display the Validation Messages in a Message Box. I want to Display these two validation Messages in a New Line.
I did like this:

ErrorMsg="";

if (TextBox1.Text == "")
{
   ErrorMsg += "Name is required!";
   ErrorMsg += "\n";
}
if (TextBox2.Text == "")
{
   ErrorMsg += "Address is required!";      
}

ScriptManager.RegisterClientScriptBlock(this.Page, typeof(UpdatePanel), Guid.NewGuid().ToString(), "window.alert('" + ErrorMsg + "')", true);
            return;

But it does not show the message box.

If I remove the coding line
ErrorMsg += “\n”;
in the above code. It simply concatenate the two strings and shows the message box.

How to display in the NewLine?

Answer 1

You will need to escape the newline like below, to stop it being output to the browser as a literal newline:

        string ErrorMsg = "";

        if (TextBox1.Text == "")
        {
            ErrorMsg += "Name is required!";
            ErrorMsg += "\\n";
        }
        if (TextBox2.Text == "")
        {
            ErrorMsg += "Address is required!";
        }

        ScriptManager.RegisterClientScriptBlock(this.Page, typeof(UpdatePanel), Guid.NewGuid().ToString(), "window.alert('" + ErrorMsg + "')", true);
        return;

This should produce the following in the browser:

window.alert('Name is required!\nAddress is required!')

Where as before this was the output (which was failing because of a newline in the string constant):

window.alert('Name is required!
Address is required!')