Validate fields

<script type="text/javascript" language = "javascript">
var ck_name = /^[A-Za-z0-9 ]{2,30}$/;
var errors = [];
var isValid;
function ValidateFields()
{
var name = jQuery("#FolderNameTextBox").val().trim();
if( 2 > name.lenght || name.lenght > 30)
{
errors[errors.length] = "Please provide name less than 30 charecters"+"\n";
}
if (!ck_name.test(name))
{
errors[errors.length] = "Please provide valid name." +"\n";
}
if(errors.length > 0)
{
reportErrors(errors);
isValid = false;
}
else
{
isValid = true;
}

}
function reportErrors(errors){
var msg = "Please enter valide data. \n";
for (var i = 0; i<errors.length; i++)
{
var numError = i + 1;
msg += "\n" + numError + ". " + errors[i];
}
alert(msg);
errors.length = 0;
}
</script>