# Error: Find distance to target unity - Siege of Stonehold (JS)

**URL:** <https://discourse.codecombat.com/t/error-find-distance-to-target-unity-siege-of-stonehold-js/2029>\
**Category:** Uncategorized\
**Created:** [December 21, 2014, 3:18pm UTC](https://discourse.codecombat.com/t/error-find-distance-to-target-unity-siege-of-stonehold-js/2029 "2014-12-21T15:18:47Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![kimamb](https://sea2.discourse-cdn.com/flex016/user_avatar/discourse.codecombat.com/kimamb/32/1797_2.png) [@kimamb](https://discourse.codecombat.com/u/kimamb)\
**Post date:** [December 21, 2014, 3:18pm UTC](https://discourse.codecombat.com/t/error-find-distance-to-target-unity-siege-of-stonehold-js/2029/1 "2014-12-21T15:18:48Z")

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Error: Find distance to target unity

```
if (this.distanceTo(enemy) < 10) {

```

Why is this an error.  
This has’nt been an error before, but on this level it is

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**Author:** ![nick](https://sea2.discourse-cdn.com/flex016/user_avatar/discourse.codecombat.com/nick/32/784_2.png) [@nick](https://discourse.codecombat.com/u/nick)\
**Post date:** [December 21, 2014, 4:41pm UTC](https://discourse.codecombat.com/t/error-find-distance-to-target-unity-siege-of-stonehold-js/2029/2 "2014-12-21T16:41:52Z")

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There probably isn’t an enemy within sight at some point; have you checked whether the enemy exists first?

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<div class="post-metadata">

**Author:** ![kimamb](https://sea2.discourse-cdn.com/flex016/user_avatar/discourse.codecombat.com/kimamb/32/1797_2.png) [@kimamb](https://discourse.codecombat.com/u/kimamb)\
**Post date:** [December 21, 2014, 8:34pm UTC](https://discourse.codecombat.com/t/error-find-distance-to-target-unity-siege-of-stonehold-js/2029/3 "2014-12-21T20:34:52Z")

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@nick No, how do i do that?

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<div class="post-metadata">

**Author:** ![lynxbob](https://avatars.discourse-cdn.com/v4/letter/l/3e96dc/32.png) [@lynxbob](https://discourse.codecombat.com/u/lynxbob)\
**Post date:** [December 21, 2014, 9:38pm UTC](https://discourse.codecombat.com/t/error-find-distance-to-target-unity-siege-of-stonehold-js/2029/4 "2014-12-21T21:38:27Z")

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To check if an enemy exists, you have to have the line of code

```python
if (enemy) {

```

because an enemy has to be there for that line to work.