object error?

When i run my update statement i get an error saying "document.form1.txtyearstart.value" is not an object"?? Any suggestions?


function btnUpdate_onclick(){


var strAddress = 'FinancialYear.asp?Action="U"' +
'&yearstart='document.form1.txtyearstart.value +
'&yearend=' + document.form1.txtyearend.value +
'&userid=<%=strStampUser%>'
window.location = strAddress
}
-->

Thanks in advance!

Try putting a + in front of the

document.form1.txtyearstart.value + ......

bit;

eg;

Code:

---

function btnUpdate_onclick(){


var strAddress = 'FinancialYear.asp?Action="U"' +
'&yearstart=' + document.form1.txtyearstart.value +
'&yearend=' + document.form1.txtyearend.value +
'&userid=<%=strStampUser%>'
window.location = strAddress
}
-->

---