未捕获类型错误：无法将属性'valueAsDate'设置为null

I am getting this weird error that I attempting to de-bug. I have an input field that has the current time pre displayed as the value. when I run the page i get the Uncaught Type error referring to the Javascript file line number 8 (document.getElemntByID("theTime").valueAsDate=b;)I am getting this weird error that I attempting