| eval is an important function as it allows you build Javascript dynamically |
| For instance document.forms[0].actualtextname.value is value of form element specified as |
| <INPUT TYPE="text" NAME="actualtextname" VALUE="value" onChange="handle(this.name)" > |
| this.name holds actualtextname but as an ascii string which cannot be directly be used in |
| var x = document.forms[0].actualtextname.value; |
| var x = eval("document.forms[0]." + actualtextname + ".value"); // works! |
| eval applies JavaScript interpreter to argument and then re-interprets as shown above |
| This can be used to copy information between forms as in |
| eval("document.forms[1]." + actualtextname + ".defaultvalue") = eval("document.forms[0]." + actualtextname + ".value") |