onClick Image tick/check the check box

onClick Image tick/check the check box

I have a Check box then a Cross Image as below.

when i click the Image, the Checkbox should get checked. I have tried the
following code. but no use.
<img src="common_images/x.png" width="13" height="13" alt="X"
onClick="this.chk.checked=true;">
Can any one help with the Javascript to accomplish it...