online invoice software

we need complete web-based with source code and copyright : accounting software with invoice facility to print / export to .pdf - .xls - .doc / email. this must be multi-company handling required for example in home page it ask for Login / Create. If Login then it ask for username/password and user can login and if Click on Create then it Create the company and ask for : - Company Name / Address / Tel / Fax / Website / Email ID / Tax Registration Number / Service Tax Number. - Invoice is required Three type "Retail Invoice" and "Tax Invoice" and "Export Invoice". Output of Invoice is required like Tally Software ([login to view URL] ). we need demo for this.