I would like to do with HTML or Javascript not with PHP an error message when the text is empty. I have created the code ,it is a part of my code form that has a text name.I have seen tutorials or same answers here but I wasn't able to do this.
<head>
<meta name="viewport" content="width=device-width, initial-scale=1">
<script src="jquery-1.7.1.min.js"></script>
<script>
function ValidateForm() {
if($("#onoma").val()=="") {
$("#error_msg").html("Field needs filling");
}
}
</script>
in the body parts I have this code :
<label class="required" for="onoma">Όνομα</label>
<input type="text" id="onoma" name="firstname" placeholder="Your name..">
One option is:
If your input textbox is inside a <form> (as it probably should be) you can just put required on the textbox and it'll validate automatically when you try to submit the form, without needing any kind of script.
Demo:
<form>
<label class="required" for="onoma">Όνομα</label>
<input type="text" id="onoma" name="firstname" placeholder="Your name.." required>
<button type="submit" name="submit">Submit</button>
</form>Documentation: https://developer.mozilla.org/en-US/docs/Web/HTML/Attributes/required
There is a variety of other built-in validation functionality in HTML5 too - see https://developer.mozilla.org/en-US/docs/Learn/Forms/Form_validation for an overview.