不应选择当前日期之前的日期

Question

我想在当前日期之前的任何日期点击日历时显示弹出消息吗？这是具有用户点击日期的功能。 setCalendarControlDate（年，月，日）具有用户选择的日期。我如何比较日期并显示错误。

function setCalendarControlDate(year, month, day) { 

calendarControl.setDate(year, month, day); 
var arguments = "changeDataGrid;day=" + day; 
arguments += ";month=" + month; 
arguments += ";year=" + year; 
// arguments += ";rowId=" + rowId; 
arguments += ";" + rowId; 
arguments += ";"; 

document.getElementById(targetControlId.id).value = arguments; 
document.forms[0].submit(); 

}

Answer 1

var selectedDate = new Date(year, month-1, day); 

var valid = selectedDate >= new Date(); 


// If today was 12th April 2011 
year = 2011; 
month = 4; 
day = 13; 

var selectedDate = new Date(year, month-1, day); 

var valid = selectedDate >= new Date(); 

valid ; //# => true 

year = 2011; 
month = 4; 
day = 11; 

selectedDate = new Date(year, month-1, day); 

var valid = selectedDate >= new Date(); 

valid ; //# => false