what is the meaning of this statement in PHP

[hedAnnobe]

.\[code\]$row['NO'] = '<a href="javascript:void(0)" onClick="openmywindow(\''.$row['bcd'].'\',\''.$row['gfh'].'\',\''.$row['test2'].'\',\''.$_REQUEST['test1'].'\')">'.$row['abc'].'</a>'\[/code\]In the above statement, what is the meaning of escaping the values in that manner such as '\'. How can i learn this?In the above statement i want to replace the php variable \[code\]$row['TEST2']\[/code\] with a static value 'OPEN', but i am getting a syntax error.