Dropdown display in datagrid

I have 2 select or dropdown to my datagrid. Since Im doing this and im using getElementByTagName. The javascript is not functioning correctly since I have 2 select tag names If could use getElementID or getElementName for the select/dropdown I think I could get it to work.

Does anyone know how to do this

Thanks


function OnChange(down)
{
var flag = true;

var dropdowns = new Array(); //Create array to hold all the dropdown lists.
// var credit = new Arry();

var gridview = document.getElementById('<%=myDataGrid.ClientID %>'); //GridView1 is the id of ur gridview.

dropdowns = gridview.getElementsByTagName('select'); //Get all dropdown lists contained in GridView1.

for (var i = 0; i < dropdowns.length; i++)
{

if (dropdowns.item(i).value == '2') //If dropdown has no selected value
{
// down.parentElement.nextSibling.children[9].style.display = dis;
var txtshow = new Array();
txtshow = gridview.getElementsByTagName('input');
txtshow.item(i).style.display = 'block';
flag = false;
}

else
{

var txtshow = new Array();
txtshow = gridview.getElementsByTagName('input');
txtshow.item(i).style.display = 'none';
}

if (dropdowns.item(i).value == '1')
{
var txtDrop = new Array();
txtDrop = gridview.getElementsByTagName('label');
txtDrop.item(i).style.display = 'block';
}
else
{
var txtDrop = new Array();
txtDrop = gridview.getElementsByTagName('label');
txtDrop.item(i).style.display = 'none';
}

if (dropdowns.item(i).value == '3') -ERROR STARTS HERE
{
var txtOption = new Array();
txtOption = gridview.getElementsByTagName('select');
txtOption.item(i).style.display = 'block';
}
else
{
var txtOption = new Array();
txtOption = gridview.getElementsByTagName('select');
txtOption.item(i).style.display = 'none';
}


}
return flag;
}
//-->
</script>

<asp:DropDownList ID="DropDownList1" runat="server" onchange="javascript:OnChange(this);" Enabled="True">
<asp:ListItem Value ="0" >Select an Action</asp:ListItem>
<asp:ListItem Value ="1" >Drop</asp:ListItem>
<asp:ListItem Value ="2" >Change</asp:ListItem>
<asp:ListItem Value ="3" >Option</asp:ListItem>
</asp:DropDownList>
</ItemTemplate></asp:TemplateColumn>


This is in another column in the datagrid. This is the dropdown I want to toggle display.

<asp:TemplateColumn HeaderText="Option" Visible="true">
    <ItemTemplate> <select id="Select1" name="option"> <option>U</option> <option>R</option> <option>P</option> <option>S</option> </select> </ItemTemplate> </asp:TemplateColumn>