Get Label control text value in java script code:
var x = document.getElementById('<%= Label1.ClientID %>').innerText;
Get text value of textbox in java script code:
Say you have a textbox like follows:
<asp:TextBox id="txtMyTextBox" runat="Server" Text="1234"></asp:TextBox>
In javascript do the following to get value:
var value = document.getElementById('<%=txtMyTextBox.ClientID%>').value;
As TextBox is server control, so on runtime this control have different client id
'<%=txtMyTextBox.ClientID%>' will return control clientid on runtime
Get value of dropdownlist in java script code:
var statePickerDropDownList = document.getElementById('<%=statePicker.ClientID%>');
var state = statePickerDropDownList.options[statePickerDropDownList.selectedIndex].value;
pass field value in Grdview to java script
http://forums.asp.net/t/1099098.aspx
<asp:TemplateField>
<ItemTemplate>
<asp:HyperLink ID="HyperLink1" runat="server" NavigateUrl=<%# String.Format("javascript:void(window.open('http://www.{0}.com'))", Eval("ProductID")) %>> HyperLink</asp:HyperLink>
</ItemTemplate>
</asp:TemplateField>