Javascript isNumeric()

After flopping around looking for a Javascript isNumeric() function, Rosetta Code came to the rescue with isFinite(num):

 string value = "123.45e7";  
 if (isFinite(value))   
 {  
  // do something  
 }  
 //Or, in web browser in URL box:  
 // javascript:value="123.45e4"; if(isFinite(value)) {alert('numeric')} else {alert('non-numeric')}