You almost certainly have something like:

var foo = 'ccc
ddd';

This will cause an unterminated string constant as the single quotes
have to be on the same line.

This occurs when you've got the following in your xslt:

var foo = '<xsl:value-of select="foo"/>';

Used on the following xml:

<foo>ccc
ddd</foo>

To avoid this, use normalize-space where needed eg:

var foo = '<xsl:value-of select="normalize-space(foo)"/>';

cheers
andrew