[SOLVED] Eval and EvalAsync

Hi,

I have the following declaration for my widget (widget_txtTotal)

var num= $(this.container).dxNumberBox({
        value: 0.00,
        format: ' #,##0.00',
        rtlEnabled: true,
        showSpinButtons: false,
        showClearButton: false,
    });
    this.total = num.dxNumberBox('instance');


Then there is a problem I don't understand the difference

async private void button1_Click(object sender, EventArgs e)
 {
    await widget_txtTotal.EvalAsync("this.total.option('value',888)"); --System.ApplicationException: 'Unable to get property 'option' of undefined or null reference'
    widget_txtTotal.Eval("this.total.option('value',888)"); //successfully executed
 }

What did I miss? Please tell me how to do it correctly.

Thank you.