MVC Razor Validation not firing on textarea - asp.net-mvc

Question

i am having a problem with validating a form in MVC Razor the Binding class is the following based off an abstract class (there is no validation in the abstract class)
[GeminiDisplayName("You are about To reject the following Purchase Order", false)]
public class PORejected : PoApprovalItems
{
public PORejected() { }
[GeminiDisplayName("Rejection Reason")]
[Required(AllowEmptyStrings = false, ErrorMessage = "Rejection Reason is Required")]
public string RejectReason { get; set; }
public override bool IsApproved
{
get
{
return false;
}
}
}
and the view is as follows
#model Gemini.Models.PORejected
#section Head{
<script src="#Url.Content("~/Scripts/jquery.validate.js")" type="text/javascript"></script>
<script src="#Url.Content("~/Scripts/MicrosoftAjax.js")" type="text/javascript"></script>
<script src="#Url.Content("~/Scripts/MicrosoftMvcAjax.js")" type="text/javascript"></script>
<script src="#Url.Content("~/Scripts/MicrosoftMvcValidation.js")" type="text/javascript"></script>
<script src="#Url.Content("~/Scripts/PageScripts/_Approval.js")" type="text/javascript"></script>
}
#section TabHeader{
<li>Reject Approval for PO #Model.PO_Number</li>
}
#section TabContent{
#{
Html.EnableClientValidation();
}
<div id="ApprovalItem">
#{
#Html.ValidationSummary(false)
using (Html.BeginForm("Approve", "PO", FormMethod.Post))
{
#Html.Partial("Approval/ApprovalDetails", Model)
<div class="display-label">
<table width="100%" cellpadding="0" cellspacing="0" border="0">
<tr>
<td width="15%">
#Html.LabelFor(x => x.RejectReason)
</td>
<td>
#Html.TextAreaFor(x => x.RejectReason, new { #Class = "mceEditor required", #style = "width:60%;" })
#Html.ValidationMessageFor(x => x.RejectReason)
</td>
</tr>
</table>
<div style="float: right;">
<input type="button" value="Close" />
<input type="submit" value="Reject" />
</div>
</div>
Html.EndForm();
}
}
</div>
}
the thing is when i click the submit button it fires off before doing any validation even though it should validate
my question is what am i doing wrong?
UPDATED
found the answer eventually i was missing the following from the page.
<script src="#Url.Content("~/Scripts/jquery.validate.unobtrusive.js")" type="text/javascript"></script>

Answer 1

found the answer eventually i was missing the following from the page. <script src="#Url.Content("~/Scripts/jquery.validate.unobtrusive.js")" type="text/javascript"></script>

Answer 2

What is this line for?
Html.EnableClientValidation(false);
This disables client validation. Also, no need to set UnobtrusiveParameters on each view, set them once in web config.