cast-and-convert

Problems converting NVARCHAR to INTEGER in SQL Server 2005 Express

Afternoon everyone, I'm having some issues converting a calculation into a INTEGER! Essentially I have the calculation; CAST(ROUND(SQRT(SQUARE(69.1*(CAST(tblPostCode.PCLat AS DECIMAL(30,15)) - "& 53.078282 &")) + SQUARE(69.1 * (CAST(tblPostCode.PCLng AS DECIMAL(30,15)) - "& -2.271495 &") * COS(CAST(tblPostCode.PCLat AS DECIMAL(30,15))...