PHPecho has a knob but cannot trigger the click event.

PHPecho has a button but cannot trigger the click event & lt ;? Php & nbsp; echo & nbsp; '& lt; input & nbsp; name = "minus" & nbsp; type = "button" & nbsp; value = "-" & nbsp; onclick = "num_minus (" PHP echo has a button, but cannot trigger the click event

 Echo'
 ';
Echo'
 
  
';
  
Echo'
  ';
  
?>
  

  
   
Function num_plus (id_num)
   
{
   
Document. getElementById (id_num). value ++;
   
// Document. getElementById ('num'). value = parseInt (document. getElementById ('num'). value) + 1;
   
// ParseInt (a, B) parses a into a hexadecimal number of B
   
}
   
Function num_minus (id_num)
   
{
   
If (document. getElementById (id_num). value = 1)
   
Document. getElementById (id_num). value = 1;
   
Else
   
Document. getElementById (id_num). value --;
   
}
   
Script
   

   

  
 

PHP button click to share to: ';... 'data-pics = ''>
------ Solution --------------------
The quotation marks you use are messy ...... Clarify
------ Solution --------------------

echo '
 ';
echo '
 
  ';
  
echo '
  ';
  

 

Onclick = "num_minus (" xx ");" an error is reported in the browser!