JavaScript not working on SelectList option

Question

I have write a javascript method on SelectList Option

<apex:selectList id="IdSelectedMembers" value="{!selectedMemberIds}" multiselect="true" size="8" style="width: 200px;" ondblclick="OpenEvent(this.id);">
<apex:selectOptions value="{!selectedMemberOption}"/>                                                    </apex:selectList>
//-----JavaScript Method ----
function OpenEvent(sVal){    
    var sValue = document.getElementById(sVal).value;   
    alert(sValue);    
    var newwindow = window.showModalDialog("/apex/EventCalendar?id="+sValue, 'open page','_blank','scrollbars=yes,toolbar=no,status=no');
    newwindow.focus();
}

I got alert msg but new window not opening. can you help me.

Answer 1

This is a deprecated method. You should use window.open() with same set of parameters

window.open("/apex/EventCalendar?id="+sValue, 'open page','_blank','scrollbars=yes,toolbar=no,status=no');