Manipulating data using ASP & SQL code

<i><b>Originally posted by : Rob (renasis@home.com)</b></i><br />Hello,<br /><br />This is my problem. I have a form page(form.asp) which includes numeric fields. I pass this information to update.asp page. Where I use the a custom SQL query to update the information. Now that I have the updated info...I use another custom SQL query to add the numbers. I store this as a variable "total". All of this data is updated in the database. Everything works fine if all of the numbers are inputed on the form.asp page. However, if one of the values is blank I get an error "One or more of the fields is empty". I could change the fields from numeric to text, but I would be unable to add the numbers. <br /><br />What should I do? Could I use the SQL DECLARE statement? Could you refer me to where I should look?<br /><br />I am using FRONTPAGE 2000 and ACCESS 2000 with ODBC.