Testing the validation of a text box using Selenium - selenium

Question

I am trying to test a webpage using Selenium and NUnit. One of my test cases entails the validation of text boxes. Using Selenium and C#, I am able to retrieve the value entered in the text box. But when the validation of the text box fails, an error message is displayed next to the text box.
So, here are my questions:
1. How can I test if an error was raised due to validation failure.
2. Can I get the text of that error.
3. Or, am I way off the mark and what I am trying to do is not at all possible.
I have tried reading the value of the element, but it always seems to be an empty string.
Say, for example, I am trying to test the webpage https://edit.yahoo.com/registration . When I enter "**myname&&" in the First Name field, an error appears stating "Only letters, spaces, hyphens, and apostrophes are allowed". I want to be able to test that this error was raised.
Also, I noticed that when Selenium opens the webpage and enters an incorrect value in the text box, the error message does not get displayed next to this text box. Whereas, when I open the webpage myself and enter an incorrect text, the error message is displayed
Thanks!!

Answer 1

You will have to use thread.sleep, but in a better way. It's better to write a function like this (I am writing this in JAVA, you should be able to write it for C#). This method will wait for the specified number of seconds for the element to be visible. If the element is not visible even after the specified number of seconds, then the method will return false. If it becomes visible then the method will return true.
Alternatively, you can use an assertion instead of returning a false condition so that your test fails.
public boolean waitForErrorMessage(String elementToWaitFor, int waitTimeInSeconds)
{
int timeOut=0;
while(!selenium.isVisible(elementToWaitFor))
{
if(timeOut<waitTimeInSeconds){
#sleep for one second
Thread.Sleep(1000);
}
else {
return false;
}
timeOut=timeOut+1;
}
return true;
}