UniqueId and ClientID in asp.net

Here i have given two scenarios to explain those importance in asp.net
In case of a control which is placed in a web form without Master Page:
The Id and Name attribute rendered to the browser are same as Id of control on server and thus the same Id/Name can be used

for programming a control in java script

In case of a control which is placed in a web form with Master Page:

The control Client side Id="<%=ServerofControl.ClientID%>" example:ct100_ContentPlaceHolderId_ServerIdofControl

The control Client side Name="<%=ServerofControl.UniqueID%>" example:ct100$ContentPlaceHolderId$ServerIdofControl

1.Add a text box and HTML button to webform/content page which has been page

<asp:TextBox runat="server" ID="txtwform"/>

<input type="button" value="cbutton" onclick="Show()"/>

2.Add the following to the web form (cphHead isId of ContentPaveHolder added to Head Section of Master Page)

<asp:Content ID="chead" ContentPlaceHolderID="cphead" runat="server">

<script>
function Show()
{
var test=document.<%=Page.Form.ame%>.<%=txtwform.UniqueID%>;
alert(test.value);
}

</scrip>