# Question about CreatePalette

**URL:** <https://community.wolfram.com/t/question-about-createpalette/7713>\
**Category:** Questions\
**Tags:** mathematica\
**Created:** [January 19, 2016, 5:01pm UTC](https://community.wolfram.com/t/question-about-createpalette/7713 "2016-01-19T17:01:06Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![ericjohnstone](https://avatars.discourse-cdn.com/v4/letter/e/f0a364/32.png) [@ericjohnstone](https://community.wolfram.com/u/ericjohnstone)\
**Post date:** [January 19, 2016, 5:01pm UTC](https://community.wolfram.com/t/question-about-createpalette/7713/1 "2016-01-19T17:01:06Z")

</div>

Hi,

I have a lot of utility functions that I’d like to make into an Algebraic Manipulation Extras.

For example, it would be nice to have a crossMultiply:

```
crossMultiply[a_==b_]:=Numerator[a] Denominator[b]==Numerator[b] Denominator[a]
CreatePalette[PasteButton[crossMultiply[\[SelectionPlaceholder]]]];

```

This doesn’t work like the Algebraic Manipulation palette: it correctly does the substitution:

```
a/b == c/d
crossMultiply[a/b == c/d]
a d == b c

```

when `a/b == c/d` is highlighted, but it returns the function `crossMultiply[a/b == c/d]` which then has to be shift/entered to evaluate.

Nothing I do can get it to evaluate automatically, which the description of PasteButton would seem to warrant. Any suggestions?

Thanks,

Eric

---

<div class="post-metadata">

**Author:** ![ericjohnstone](https://avatars.discourse-cdn.com/v4/letter/e/f0a364/32.png) [@ericjohnstone](https://community.wolfram.com/u/ericjohnstone)\
**Post date:** [January 19, 2016, 11:29pm UTC](https://community.wolfram.com/t/question-about-createpalette/7713/2 "2016-01-19T23:29:07Z")

</div>

The solution was in tutorial/CreatingPalettes:

```
CreatePalette@
    Button[Defer[#[\[SelectionPlaceholder]]], Inherited, 
     BaseStyle -> "Evaluate", Evaluator -> None, 
     Appearance -> "Palette"] & /@ {crossMultiply};

```

Eric