var errormsg="";
function checkEmail(email,s)
{
   var at1      =  email.indexOf("@");
   var at2      =  email.lastIndexOf("@");
   var dot     =  email.lastIndexOf(".");
   var space   =  email.indexOf(" ");
   if((at1!=-1)&&
      (at1!=0)&&
      (at2==at1)&&
      (dot!=-1)&&
      (dot>at1+1)&&
      (dot<email.length-1)&&
      (space==-1))
   {
      return true;
   }
   else
   {
      errormsg=errormsg+"- "+s+".\n";
      return false;
   }
}
function checkDate(dd,mm,yyyy,name)
{
   result=true;
   if(!isNaN(yyyy)&&(yyyy!="")&&(yyyy<10000))
   {
      if( (mm=="02") && ((dd=="30")||(dd=="31")) )
         result=false;
      if( (mm=="02") && (dd=="29") && (yyyy%4>0) )
         result=false;
      if( ((mm=="04")||(mm=="06")||(mm=="09")||(mm=="11")) && (dd=="31") )
         result=false;
   }
   else
   {
      result=false;
   }
   if(result==false)
      errormsg=errormsg+"- "+name+" khong dung dinh dang.\n"
   return result;
}
function checkInterval(dstart,mstart,ystart,names,dend,mend,yend,namee)
{
   var re=true;
   re=checkDate(dstart,mstart,ystart,names)&&checkDate(dend,mend,yend,namee);
   if(re)
   {
      var yyyy=yend-ystart;
      if(yyyy>0)
	 		re=true;
      else if(yyyy==0)
      {
         var mm=mend-mstart;
         if(mm>0)
            re=true;
         else if(mm==0)
         {
            var dd=dend-dstart;
	    	if(dd>=0)
	       	re=true;
         else
            re=false;
         }
         else
	    		re=false;
      }
      else
         re=false;
   }
   if(re==false)
      errormsg=errormsg+"- Illegal interval time.\n";

   return re;
}
function checkTextField(str,name)
{
	if(str=="")
	{
		errormsg=errormsg+"- "+name+".\n";
		return false;
	}
	else
		return true;
}

function checkPassword(p,namep,rp,namerp)
{
	if(p!=="")
	{
		if(p==rp)
	 		return true;
	 	else
		{
			errormsg=errormsg+"- "+namep+" khong giong voi "+namerp+".\n";
			return false;
		}
	}
	else
	{
		errormsg=errormsg+"- "+namep+" chua co thong tin.\n";
		return false;
	}

}

function checkIsIntNum(val,name)
{
	if((val!="")&&(!isNaN(val)) && val.indexOf(".")<0)
		return true;
	else
	{
		errormsg=errormsg+"- "+name+" khong phai la so nguyen.\n";
		return false;
	}
}

function checkChoice(val,name)
{
	if(val=="")
		errormsg=errormsg+"- "+name+" phai chon mot.\n";
}

function checkIsNum(val,name)
{
	if((val!="")&&(!isNaN(val)))
		return true;
	else
	{
		errormsg=errormsg+"- "+name+" khong phai la mot so.\n";
	}

}
function checkAll()
{
	if(errormsg!="")
	{
		alert(errormsg);
		errormsg="";
		return false;
	}
	else
		return true;
	errormsg="";
}
function setCheckboxes(the_form, the_box, do_check)
{
    var elts      = (typeof(document.forms[the_form].elements[the_box]) != 'undefined')
                  ? document.forms[the_form].elements[the_box]
                  : document.forms[the_form].elements[the_box];
    var elts_cnt  = (typeof(elts.length) != 'undefined')
                  ? elts.length
                  : 0;

    if (elts_cnt) {
        for (var i = 0; i < elts_cnt; i++) {
            elts[i].checked = do_check;
        }
    } else {
        elts.checked        = do_check;
    }
    return true;
}

function checkCheckboxes(the_form, the_box)
{
   var elts      = (typeof(document.forms[the_form].elements[the_box]) != 'undefined')
                  ? document.forms[the_form].elements[the_box]
                  : document.forms[the_form].elements[the_box];
   var elts_cnt  = (typeof(elts.length) != 'undefined')
                  ? elts.length
                  : 0;
	err=false;

	if (elts_cnt)
   {
		for (var i = 0; i < elts_cnt; i++)
		{
			if(elts[i].checked == true)
			{
				err=true;
				break;
			}
		}

	}
	else if(document.forms[the_form].elements[the_box].checked==true)
	{
		err=true;
	}

	return err;
}

function checkSelections(the_form, the_box)
{
   var elts      = (typeof(document.forms[the_form].elements[the_box]) != 'undefined')
                  ? document.forms[the_form].elements[the_box]
                  : document.forms[the_form].elements[the_box];
   var elts_cnt  = (typeof(elts.length) != 'undefined')
                  ? elts.length
                  : 0;
	err=false;

	if (elts_cnt)
   {
		for (var i = 0; i < elts_cnt; i++)
		{
			if(elts[i].selected == true)
			{
				err=true;
				break;
			}
		}

	}
	else if(document.forms[the_form].elements[the_box].selected==true)
	{
		err=true;
	}

	return err;
}

function checkZeroValue(the_form,the_box)
{

	var elts      = (typeof(document.forms[the_form].elements[the_box]) != 'undefined')
	                  ? document.forms[the_form].elements[the_box]
	                  : document.forms[the_form].elements[the_box];
	var elts_cnt  = (typeof(elts.length) != 'undefined')
						? elts.length
						: 0;
	err=false;

	if (elts_cnt)
	{
		for (var i = 0; i < elts_cnt; i++)
		{
			if(elts[i].value == "")
				elts[i].value = "0";
			if(elts[i].value != "0")
			{
				err=true;
				break;
			}
		}
	}
	else if(document.forms[the_form].elements[the_box].value!="")
	{
		err=true;
	}
	return err;
}