Question

I have a javascript function below to move from select multiple box A which is populated from database to another multiple select box B, in the event of a postback my values in B which are moved over from A got lost. Initially I thought because I included a “runat=”server”” tag for server side actions but apparently it’s not the case. I read about Form.Request but ain’t have a clue how to go about it. I just need to retain those values in multiple select box B. Please kindly advice. Thanks.

<%– Move items to and fro select box –%>

function move(sourceFrom, sourceTo) {
    var arrFrom = new Array();
    var arrTo = new Array();
    var arrLU = new Array();
    var i;
    for (i = 0; i < sourceTo.options.length; i++) {
        arrLU[sourceTo.options[i].text] = sourceTo.options[i].value;
        arrTo[i] = sourceTo.options[i].text;
    }
    var fLength = 0;
    var tLength = arrTo.length;
    for (i = 0; i < sourceFrom.options.length; i++) {
        arrLU[sourceFrom.options[i].text] = sourceFrom.options[i].value;
        if (sourceFrom.options[i].selected && sourceFrom.options[i].value != "") {
            arrTo[tLength] = sourceFrom.options[i].text;
            tLength++;
        } else {
            arrFrom[fLength] = sourceFrom.options[i].text;
            fLength++;
        }
    }

    sourceFrom.length = 0;
    sourceTo.length = 0;

    var ii;
    for (ii = 0; ii < arrFrom.length; ii++) {
        var no = new Option();
        no.value = arrLU[arrFrom[ii]];
        no.text = arrFrom[ii];
        sourceFrom[ii] = no;
    }

    for (ii = 0; ii < arrTo.length; ii++) {
        var no = new Option();
        no.value = arrLU[arrTo[ii]];
        no.text = arrTo[ii];
        sourceTo[ii] = no;
    }

    (sourceTo).focus();

    if (sourceTo == (document.getElementById('<%= outletFromBox.ClientID%>'))) {
        (sourceFrom).focus();
    }
    if (sourceTo == (document.getElementById('<%= QualMemTypeFromBox.ClientID %>'))) {
        (sourceFrom).focus();
    }
    if (sourceTo == (document.getElementById('MemStatusFromBox'))) {
        (sourceFrom).focus();
    }
}  
<select multiple size="8" style="width: 135px" runat="server" onblur="selectAll(this, true, document.getElementById('<%#uilblDestinationQualOutlet.ClientID%>'))"
                                        id="outletToBox">
                                    </select>

Answer 1

Client-side changes to a ListBox are not persisted server-side, so any changes made will be lost if a PostBack occurs; check out this link to see how you can handle it:

http://www.vijaykodali.com/Blog/post/2007/12/14/Add-Delete-Items-in-DropDownList2c-ListBox-using-Javascript.aspx

If you’re having trouble working with that solution let me know, and post your aspx page code…we can put together a solution for your exact case.