I am creating a subiste by using the below javascript code.I want to check if a subsite exists or not before creating it. I ma creating a susiste on button click function like below

<

    div>
    
        <input type="test" id="text" /><input type="button" id="button" value="Create Site " />
        </div>
        
        $('#button').click(function() {
        var mytest= $("#text").val();
        alert(mytest);
         createWebsite(mytest);
          
        });
    
     
    
    
 

Can any one help me on this . 

Creating a subsiste function
    
         function createWebsite(SiteName) {
        
            var clientContext = SP.ClientContext.get_current();;
            var collWeb = clientContext.get_web().get_webs();
            var webCreationInfo = new SP.WebCreationInformation();
            webCreationInfo.set_title(SiteName);
            webCreationInfo.set_description('Description of new Web site...');
            webCreationInfo.set_language(1033);
            webCreationInfo.set_url(SiteName);
            webCreationInfo.set_useSamePermissionsAsParentSite(true);
            webCreationInfo.set_webTemplate(siteTemplate);
              var oNewWebsite = collWeb.add(webCreationInfo);
            clientContext.executeQueryAsync(Function.createDelegate(this, this.onQuerySucceeded), Function.createDelegate(this, this.onQueryFailed));
        }
        
        function onQuerySucceeded() {
            alert("Created Web site.");
        }
        
        function onQueryFailed(sender, args) {
            alert('Request failed. ' + args.get_message() + '\n' + args.get_stackTrace());
        }