var a = contentPane.parameterEl.getWidgetByName("文本框控件名");
var AValue = a.getValue();
var b = contentPane.parameterEl.getWidgetByName("结束日期控件名").getValue();
if (b >='1' && (AValue == null || AValue == undefined || AValue == '')) {
alert("结束日期搜索条件必填");
a.options.allowBlank = false;//这里设置控件不可为空(true可为空)
} else {
a.options.allowBlank = true;
}