==== strins ====

Insert a substring in a string

=== Description ===

<code>strins( string[], const substr[], index, maxlength=sizeof string )</code>

Inserts a substring into a string. 

=== Parameters ===

| ''string'' | The string that will be manipulated |
| ''substr'' | The string that will be inserted |
| ''index'' | The location in ''string'' where the ''substr'' will be inserted. If 0, the substr will be prepended to string |
| ''maxlength'' (optional) | The size of dest in cells |

=== Return value ===

Returns 1 on success, 0 on failure.

=== Example usage ===

<code javascript>    
    new s{40} = "CatAnt";
    new b{20} = "Dog";

    strins(s, b, 3);  // returns 1

    // s now contains "CatDogAnt"
</code>