Hi i need to  get the value  total VAT Inc Field . in the Message once i release the Sales order the message is Showing  zero value . but again if i click it it shows the TOTAL VAT VALUES . but how to get the statistics form field value TOTAL VAT INC when i release the order itself here is my code

this is the field i need to get in the message when the status is open and should get while i release it. but message is displaying first with value zero . after once the status is release then the message is showing the value . but i need the calculated and get the message once I click it . can any one help . this is the field

in the Sales order Statistics

pls can any one help it out