onChange event in javascript

Question

i wanna do that if i select value of list item in dropdown then hide some textbox and some dropdown control... i tried it but i got error that now my function hit but not got a value.... plz someone help me... i m thanking you.... plz help me ......

 

 

 

this is my scirpt function:-

<script type="text/javascript">

function ChangeText() {

debugger;

$("#course").change(function () {

alert($("#course").val());

if ($(this).val() == "B.Tech[PCB Group]") {

$('#div_graper').hide();

$('#div_yearofgra').hide();

}

});

};

my dropdown control:-

<div id="select">

<asp:DropDownList ID="course" runat="server" class="slectbig" data-bind="event" onChange="ChangeText()" >

<asp:ListItem Value="Select Course "></asp:ListItem>

<asp:ListItem Value="B.Tech[PCB Group]">B.Tech[PCB Group]</asp:ListItem>

<asp:ListItem Value="Polytechnic">Polytechnic</asp:ListItem>

<asp:ListItem Value="MBA">MBA</asp:ListItem>

<asp:ListItem Value="BBA">BBA</asp:ListItem>

<asp:ListItem Value="B.Pharma">B.Pharma</asp:ListItem>

</asp:DropDownList>

my textbox control:-

<div id="div_graper" style="width: 250px; " class="option">

<asp:TextBox ID="gradutionper" runat="server" placeholder="gradution %" ></asp:TextBox>

</div></div>

<div class="clear"></div>

</div>