Markup Validator bug fix

An "&" character in the "src" field of the "img" tag throws a series of 
errors beginning with:
/

Line 126, Column 44/: cannot generate system identifier for general 
entity "sml".

|<img height=225 width=300 src="pie.php?id=1&*s*ml=1" alt="Religions"><br>|

✉ 
<http://validator.w3.org/feedback.html?uri=http%3A%2F%2Fwww.causal.ca%2Fgraph%2Fcanvas.php;errmsg_id=338#errormsg> 


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* as described by the WDG <http://www.htmlhelp.com/> in "Ampersands 
in URLs <http://www.htmlhelp.com/tools/validator/problems.html#amp>".

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