1. A computer-implemented method for providing an integrated data source from at least two disparate data sources, the method comprising: receiving a request from a user to access a webpage to apply for a product; in response to receiving the request to access the webpage, searching the at least two disparate data sources to determine a set of common data elements that includes data items related to the identified user, at least some of the data items needed for a web document for applying for the product, the data items including information about the user previously entered by the user; storing, by a computing device, the set of common data elements and associated data items related to the identified user in a database; for at least one common data element in the set of common data elements: comparing a first format of a first data item needed for the web document from the first data source with a second format of a second data item needed for the web document from the second data source, identifying a difference in the first format and the second format based on the comparison, in response to identifying the difference in the formats, selecting a preferred format for the web document, generating a modified common data element in which at least one of the first data item or the second data item is modified in accordance with the preferred format; and automatically generating the web document using the modified common data element so that the user does not have to re-enter the information about the user.