I tried to find the answer in other questions but actually nothing worked -.- Somehow I hate JavaScript ... Anyway! My Code looks like:

function validate()
{
 if ($(":input").length == 0) 
 {
  $(":input").addClass("notvalid");
  return false;
 }
 else
 {
  $(":input").removeClass("notvalid");
  return true;
 } 

 return true;
}

$(":input").blur(validate());
$(":input").keyup(validate());

$("#customForm").submit(function(){
 if(validate()){
  return true;
 }
 else
 {
  return false;
 }
});

I just want to test every tag to be not empty. The test should be done when the focus is lost or after every key type. And of course after the submit button has been clicked.

It doesn't work. Firefox error console says something like: unknown pseudoclass or pseudoelement 'input'. What does this mean?