unable to get the value of button inside update panel

Question

Team,

When I click on the first add template button then the download value disappear. .

window.onload = function() {
    ddnameChange();
};
function ddnameChange() {
    var e = document.getElementById("<%=ddltemplate.ClientID %>");
    var ddnamevalue = e.options[e.selectedIndex].value;    
    if(ddnamevalue==2)
    {       
        <%=btndownload.ClientID %>.value="Download RBH Template";

    }
    else if(ddnamevalue==3)
    {
        <%=btndownload.ClientID %>.value="Download VISTA Template";
    }
    else
    {
        <%=btndownload.ClientID %>.value="Download OD Template";  
    }
}

I am not able to get the second button value when i click on edit as well as all template button.I know it should be something reason like update panel that why the function is not calling I don't know how to solve it.

Answer 1

You have to add this in the method that handles the Async PostBack.

ScriptManager.RegisterStartupScript(Page, Page.GetType(), "ddnameChange", "ddnameChange();", true);

When the Async PostBack occurs, everyting inside the UpdatePanel is rebuild and anything that has been altered by jQuery will be lost.