Problem was in blank text in c# doing edit from gridview?

Question

Hai Friends,


i ve the application like


departure date=textbox
No.of.days = textbox
Lodge = textbox (created on event for validation)
Food Bill = textbox
Daily Claim =textbox
other Bills = textbox

add(after press these Button entire details ll show gridview)
Update (Button)

Grdview

departuredate no.of.days lodge food bill dailyclaim otherBills details
edit


here the problem is when i choose "EDIT" from gridview details cum above textbox perfectly sum columns are NULL means after edit it contains "&nsbp;" like that please refer attachment.


and one more problem

i need the validation when ppl choose Lodge & food Bill

Daily claim is on read only.(daily claim choosed means Lodge & Food Bill read only)
i made the code like that


protected void TxtLdg_TextChanged(object sender, EventArgs e)
{
if ((TxtLdg.Text.Length >= 1) )
{

TxtFdAl.ReadOnly = true;

}
else if ((TxtFdAl.Text.Length >= 1))
{

TxtLdg.ReadOnly = true;
TxtFoAl.ReadOnly = true;

}
else
{
TxtFdAl.ReadOnly = false;
TxtLdg.ReadOnly = false;
TxtFoAl.ReadOnly = false;

}

}

if i choose Daily allowance directly then choose " other Bills " means Lodge and FoodBill on read only,before choosed "other Bills" i entered value on lodge and food with Daily claim means ll taken that?


how to short out 2 problems?