custom validator for Radcombo and checkbox

CustomValidator ID="CusAccountcard" runat="server" ClientValidationFunction="Valaccountcard"
ControlToValidate="DropDownAccountCard" Display="Dynamic" ErrorMessage="Please select account card"
ValidationGroup="Save" asp:CustomValidator

function Valaccountcard(sender,args)
{

var combo =<%=DropDownAccountCard.ClientID %>;
if(combo.GetText()!="Select")
{
args.IsValid = true;
}
else
{
args.IsValid = false;
}

}



function Validate(sender,args)
{

var combo =<%=ddExpMonth.ClientID %>;
if(combo.GetText()!="Select")
{
args.IsValid = true;
}
else
{
args.IsValid = false;
}
var d=new Date();


}



function ValidateYear(sender,args)
{
var combo =<%=ddExpYear.ClientID %>;
if(combo.GetText()!="Select")
{
args.IsValid = true;
}
else
{
args.IsValid = false;
}

}



function ValidationCheck (sender,args)
{
if(document.getElementById('ctl00_Content1_chkAccept').checked==true)
{

args.IsValid=true;

}
else
{
args.IsValid=false;
}
}