reference not terminated by REFC delimiter

well its obvious i would run into problems someday trying to put in another code… ??
Any howto on this….(only important piece is posted….)
The first error is……
…statischklik.php?74eurob&euro&banner” target”_blank”/>
this is what w3 says……………………….
If you meant to include an entity that starts with “&”, then you should terminate it with “;”. Another reason for this error message is that you inadvertently created an entity by failing to escape an “&” character just before this text.
the second error is….
/stats2/statischklik.php?74eurob&euro&banner” target”_blank”/>
this is what w3 says……………………….
An entity reference was found in the document, but there is no reference by that name defined. Often this is caused by misspelling the reference name, unencoded ampersands, or by leaving off the trailing semicolon (;). The most common cause of this error is unencoded ampersands in URLs…………
( btw ….the B of banner was marked red)
And then related errors to the above….
1 general entity “banner” not defined and no default entity
2 reference to entity “banner” for which no system identifier could be generated
Please any help on this and what i need to change please…. ??
Be clear…..if possible….:)